In recent years, many researchers have begun to shift their focus onto the synthesis of nanomaterials as this field possesses immense potential that may provide incredible technological advances in the near future. The downside of conventional synthesis techniques, such as co-precipitation, sol-gel and hydrothermal methods, is that they necessitate the use of toxic chemicals, produce harmful by-products and require a considerable amount of energy; therefore, more sustainable fabrication routes are sought after. Biological molecules have been previously utilised as precursors to nanoparticle synthesis, thus eliminating the negative factors involved in traditional methods. In addition, transition-metal nanoparticles possess a wide scope of applications due to their multiple oxidation states and large surface areas; thereby allowing for a higher reactivity when compared to their bulk counterpart and rendering them an interesting research topic. However, this field is still relatively unknown and unpredictable. Therefore, this review aims to obtain a better understanding on the plant-mediated synthesis process of the major transition-metal and transition-metal oxide nanoparticles, and how different parameters affect their unique properties.

Methyl Mercaptan is a sulfur-based chemical found as a co-product in produced natural gas and causes corrosion in pipelines, storage tanks, catalysts, and solid adsorption beds. To improve the quality of methane produced, researchers studied the use of metal oxides and aluminum silicates as catalysts for removing mercaptan. However, there are restricted limitations on the efficiency of metal oxides or aluminum silicates as adsorbents for this particular application. Therefore, this study investigated the performance of these materials in a fixed-bed reactor with simulated natural gas streams under various operating conditions. The testing procedure includes a detailed assessment of the adsorbent/catalysts by several techniques, such as Braeuer-Emmett-Teller (BET), Scanning Electron Microscope (SEM), Energy-Dispersive X-ray Spectrometry (EDS), and X-ray Photoelectron Spectroscopy. The result revealed that metal oxides such as copper, manganese, and zinc performed well in methyl mercaptan elimination. The addition of manganese, copper, and zinc oxides to the aluminum silicate surface resulted in a sulfur capacity of 1226 mg S/g of catalyst. These findings provide critical insights for the development of catalysts that combine metal oxides to increase adsorption while reducing the production of byproducts like dimethyl sulfide (DMS) and dimethyl disulfide (DMDS) during methyl mercaptan removal.

Nanomaterials based on metal oxides (MexOy) are employed as catalysts and/or sorbents in processes undergoing conditions in supercritical water (scH2O), the “green” reaction medium used to obtain energy relevant products. Their properties are greatly affected by the synthesis method used to produce the active MexOy. Moreover, in order to maintain their performance, it is more practical and cost-effective to use supported MexOy nanoparticles. Within this context, the present work deals with the preparation of carbon-supported ZnO and CuO composites by an innovative method based on impregnation under scH2O conditions. Metal oxides were impregnated on a carbon (C) support using a continuous flow tubular reactor. The results show that impregnation in scH2O is a promising approach for the preparation of ZnO/C and CuO/C composite materials. This one-step synthesis method, in a continuous flow, uses neither seed layer nor mineralizer, and it needs substantially lower preparation times than the conventional impregnation methods.

Due to the optical properties of the Electron Transport Layer (ETL) and Hole Transport Layer (HTL), inverted perovskite solar cells can perform better than traditional perovskite solar cells. It is essential to compare both types to understand their efficiencies. In this article, we studied inverted perovskite solar cells with NiOx/CH3NH3Pb3/ETL (ETL = MoO3, TiO2, ZnO) structures. Our results showed that the optimal thickness of NiOx is 80 nm for all structures. The optimal perovskite thickness is 600 nm for solar cells with ZnO and MoO3, and 800 nm for those with TiO2. For the ETLs, the best thicknesses are 100 nm for ZnO, 80 nm for MoO3, and 60 nm for TiO2. We found that the efficiencies of inverted perovskite solar cells with ZnO, MoO3, and TiO2 as ETLs, and with optimal layer thicknesses, are 30.16%, 18.69%, and 35.21%, respectively. These efficiencies are 1.5%, 5.7%, and 1.5% higher than those of traditional perovskite solar cells. Our study highlights the potential of optimizing layer thicknesses in inverted perovskite solar cells to achieve higher efficiencies than traditional structures.

This research focusing on the environmental impact of tire and brake pad wear constitutes a significant area of transport-related studies. These two key vehicle components are not only the most frequently worn, but also generate micro and nano pollutants (i.e., rubber, metal oxides) that potentially harm the environment. Over half of the globally produced natural and synthetic rubbers, which amounted to about 30 million tons in 2022, are used for tire production. According to Wagner et al.'s research, over 1.3 million tons of such particles are released due to wear and tear in the European Union alone. This work focuses on examining snow deposits from various locations in an urban agglomeration (Poznan, Poland) in the winter season. FT-IR and NMR spectroscopic studies, optical and electron scanning microscopy SEM-EDS, and particle size studies using the DLS technique were conducted for a detailed characterization of pollutants in the environment. The conducted particle separation methods allowed for the extraction of a fraction mainly containing gum residues with particle sizes less than 2 µm. The results of these studies are crucial for understanding the impact of vehicle part exploitation on the environment.

The present review article concludes with three different types of materials recently used to enhance the efficiency of supercapacitors. The first type involves carbon-based materials for storage and supercapacitor applications. The carbon materials could be obtained naturally and synthesized manually based on the needs. The second type discusses the recent advances in metal oxide materials for high-performance supercapacitors. The metal oxide materials involve in different types of attachment through the bi-tri metallic bonding, which enhances the specific capacitance. The third type involves recently advanced materials for high energy and power density application. The power and energy density of the materials is enhanced by the surface modification of the materials. In recent days, the MXene and Nano-composite materials seems to be an appropriate material to increase the power and energy density of the device.

Aptamers are synthetic single stranded oligonucleotides that exhibit selective binding properties to specific targets, thereby providing as powerful basis for the development of selective and sensitive (bio)chemical assays, such as biosensors. Electrochemical biosensors, utilizing aptamers as biological recognition elements, namely aptasensors, are at the forefront of current research. They exploit the combination of the unique properties of aptamers with the advantages of electrochemical detection with the view to fabricate inexpensive and portable analytical platforms for rapid detection in point-of-care (POC) applications or on-site monitoring. The immobilization of aptamers on suitable substrates is of paramount importance with the aim to retain their functionality and optimize the sensors’ sensitivity. This work describes different immobilization strategies for aptamers on the surface of semiconductor-based working electrodes, including metal oxides, conductive polymers and carbon allotropes. These are presented as platforms with tunable band gaps and different surface morphologies for the preparation of low cost, highly versatile aptasensor devices in analytical chemistry. A survey of the current literature is provided, discussing each analytical method. Future trends envisage for aptamer-based biosensing using semiconductors are also outlined.

A mild, efficient, and photocatalytic synthesis of 6-phosphorylated phenanthridines via tandem radical addition/cyclization/aromatization of 2-isocyanobiphenyls with diarylphosphine oxides is reported. The method features operational simplicity, metal-free conditions, using low-cost rose Bengal as catalyst and sustainable air as terminal oxidant at room temperature, and providing the desired products in moderate to good yields.

This work investigated the fabrication, properties, and sensing applications of TiO2 nanotubes. A purity of 99.7% and 1mm thickness of titanium metal sheet was used to elaborate titanium dioxide nanotubes for gas sensor application through electrochemical anodization in a mixture of Ethylene glycol (EG)/NH4F electrolytes. As a result, X-ray diffraction indicates the crystallization of the titanium dioxide layer. Scanning electron microscopy and Transmission electron microscopy reveal that the average diameter of the TiO₂ nanotubes is approximately 100 nm, with tube length ranging between 3 and 9 microns and a thickness of the nanotube walls of about 25 nm. This type of TiO2 nanotube is suitable for NO2 gas sensor applications. As a result, at an oxidation time of 15 min, the detection of TiO2 nanotube gas toward NO2 gas shows a good result at 250 °C, when exposed to a NO2 gas flow of 100 ppm, where a maximum NO2 gas response of 96% was obtained. The sensors based on the TiO2 nanotube arrays for sensing NO2 all exhibited high stability, good reproducibility, and high sensitivity. This work suggests that TiO2 nanotubes are a promising material for application as a NO2 sensor, as well as other applications.

Microwave plasma-driven nitrogen fixation can occur at atmospheric pressure without greenhouse gas emissions. However, this method still faces the challenge of high energy consumption and low production. Plasma-catalyst combined systems are widely used to increase production and reduce energy consumption in nitrogen fixation. However, the efficacy of current catalysts remains limited. In this paper, the metal-organic framework materials CuBTC and ZIF-8 are combined with the atmospheric microwave plasma for nitrogen fixation. The experimental results show their better catalytic effect than the ordinary catalyst ZSM-5. The maximum nitrogen oxide concentration reaches 33400 ppm, and the lowest energy consumption is 2.05 MJ/mol. Compared to no catalyst, the nitrogen oxide production can be increased by 17.1%, and the energy consumption can be reduced by 14.6%. The transmission electron microscopy (TEM) images of the catalysts reveal obvious differences in the catalyst particle sizes. Notably, catalysts with smaller particle sizes attain higher NOx concentrations compared to their larger counterparts. To the knowledge of the authors, this is the first effort to study the synergistic effects of atmospheric microwave plasma and metal-organic framework materials on nitrogen fixation.

The highly crystalline ZnAl Layered Double Hydroxides (ZnAl-NO3- LDHs) are utilized for the potential transformation into Mixed Metal oxides (MMO) through thermal decomposition and used further for the photodegradation of phenol to assess the influence of calcination on ZnAl LDHs with enhanced photoactivity. The structure, composition, and morphological evolution of ZnAl-LDHs to ZnO-based MMO nanocomposites, which are composed of ZnO and ZnAl2O4, after calcination at different temperatures (400-600 ºC), are all thoroughly examined in this work. The final ZnO and ZnAl2O4 base nanocomposites showed enhanced photocatalytic activity. The findings demonstrated that calcining ZnAl-LDHs from 400 to 600 °C increased the specific surface area and also enhanced the interlayer spacing of d003 while the transformation of LDHs into ZnO/ZnAl2O4 nanocomposite through calcining the ZnAl-LDH precursor at 600 °C showed significant photocatalytic properties, leading to complete mineralization of phenol under UV irradiation.

In this paper we present magnetoelectric properties of metal/metal-oxide/metal junctions. We use Ti and Fe as metallic layers separated by the porous metal-oxides of iron or titanium formed with the anodization method. This allowed to prepare double junctions with at least one ferromagnetic layer. Here we show magnetoresistance and current-voltage characteristics of the junctions together with their magnetic characteristics. We found positive or negative magnetoresistance depending on junction composition. We discuss also the nature of differential resistance calculated from I-V characteristics. Our findings show that the strongest influence on observed behaviour has a top metallic layer and the interface between this layer and anodized oxide where strong interatomic diffusion is expected.

Hybrid inorganic-polymer nanocomposites can be employed in diverse applications due to the potential combination of desired properties from both the organic and inorganic components. The use of novel bottom-up in situ synthesis methods for the fabrication of these nanocomposites is advantageous compared to top-down ex situ mixing methods, as it offers increased control over the structure and properties of the material. In this review, the focus will be on the application of the sol-gel process for the synthesis of inorganic oxide nanoparticles in epoxy and polysiloxane matrices. The effect of the synthesis conditions and the reactants used on the inorganic structures formed, the interactions between the polymer chains and the inorganic nanoparticles, and the resulting properties of the nanocomposites are appraised from several studies over the last two decades. Lastly, alternative in situ techniques and the applications of various polymer-inorganic oxide nanocomposites are briefly discussed.

Increasing the energy density and power of supercapacitors through hybrids of carbonaceous materials and metal oxides continues to be the subject of numerous research works. The correlation between specific capacitance and the properties of materials used as electrodes attracts great interest. In the present study, we have investigated composites (GO/Mn3O4) prepared by hydrothermal method with variable ratio GO/Mn3O4 and tested as supercapacitor electrode materials in three and two-electrode cells. The chemical characterization carried out by X-ray Photoelectron Spectroscopy and the adsorption techniques used have allowed the determination of the surface carbon and oxygen content, as well as its textural properties. In this work we have analyzed the contribution of the double layer and of the Faradaic reactions to the value of the final supercapacitance of the synthesized materials. Beyond empirically obtaining the electrochemical properties, these have been related to the physicochemical characteristics of the hybrids, to help design materials with the best performances for supercapacitor electrodes.

Biopolymers are of growing interest, but to improve some of their poor properties and performance, it is required the formulation of bio-based blends and/or adding of nanoparticles. For this purpose, in this work, two different metal oxides, such as zinc oxide (ZnO) and titanium dioxide (TiO2), at different concentrations (0.5, 1 and 2 %wt.) have been added in polylactic acid (PLA) and polylactic acid/polyamide 11 (PLA/PA11) blends to establish their effects on solid-state properties, morphology, melt behaviour, and photo-oxidation resistance. It seems that the addition of ZnO in PLA leads to a significant reduction of its rigidity probably due to an inefficient dispersion in the melt state, while the addition of TiO2 does not penalise PLA rigidity. Interestingly, the addition of both ZnO and TiO2 in PLA/PA11 blend has a positive effect on the rigidity because of blend morphology refinement and leads to a slight increase in film hydrophobicity. The photo-oxidation resistance of neat PLA and PLA/PA11 blend is significantly reduced due to the presence of both metal oxides, and this must be considered when designing the potential applications. The last results suggest that both metal oxides could be considered as photo-sensitive degradant agents for biopolymer and biopolymer blends.

Food preservatives are compound that are used for the treatment of food to improve the shelf life. In the food industry, is necessary to monitor all processes, for both safety and quality of the product. An electronic nose (or e-nose) is a biomimetic olfactory system that could find numerous industrial applications, including food quality control. Commercial electronic noses are based on sensor arrays composed by a combination of different sensors, which include conductometric metal oxide devices. Metal oxide nanowires are considered among the most promising materials for the fabrication of novel sensing devices, which can enhance the overall performances of e-noses in food applications. In the present work, is reported the fabrication of a novel sensor array based on SnO2, CuO and WO₃ nanowires deposited on top of commercial μHPs, provided by ams Sensor Solutions Germany GmbH. The array was tested for the discrimination of four typical compounds added to food products or used for their treatment to increase the shelf life: ethanol, acetone, nitrogen dioxide and ozone. Results are very promising: the sensors array was able to operate for long time consuming less than 50mW for each single sensor, and PCA analysis confirms that the device was able to discriminate between different compounds.

Knowledge about the formation energies of compounds is essential to derive phase diagrams of multi-component phases with respect to elemental reservoirs. The determination of formation energies using common (semi-)local exchange-correlation approximations of density functional theory (DFT) exhibits well-known systematic errors if applied to oxide compounds containing transition metal elements. In this work, we generalize, reevaluate and discuss a set of approaches proposed and widely applied in the literature to correct for errors arising from the over-binding of the O2 molecule and from correlation effects of electrons in localized transition-metal orbitals. The DFT+U method is exemplarily applied to iron oxide compounds, and a procedure is presented to obtain U values, which lead to formation energies and electronic band gaps comparable to experimental values. Using such corrected formation energies, we derive the phase diagrams for LaFeO3, Li5FeO4 and NaFeO2, which are promising materials for energy conversion and storage devices. A scheme is presented to transform the variables of the phase diagrams from the chemical potentials of elemental phases to those of precursor compounds of a solid-state reaction, which represents the experimental synthesis process more appropriately. The discussed workflow of methods can directly be applied to other transition metal oxides.

Efficient oxygen evolution reaction (OER) electrocatalysts are highly desired in the field of water electrolysis and rechargeable metal-air batteries. In this study, a chelate polymer, composed of copper (II) and dithiooxamide, was used to derive an efficient catalytic system for OER. Upon potential sweep in 1M KOH, copper (II) centers of the chelate polymer were transformed to CuO and Cu(OH)2. The carbon-dispersed CuO nanostructures formed a nanocomposite which exhibits an enhanced catalytic activity for OER in alkaline media. The nanocomposite catalyst has overpotential of 280 mV (at 1 mA/cm2) and a Tafel slope of 81 mV/dec in 1M KOH solution. It has a seven-fold higher current than IrO2/C electrode, per metal loading. A catalytic cycle is proposed, in which, CuO undergoes electrooxidation to Cu2O3 that further decomposes to CuO with releasing oxygen. This work reveals a new method to produce an active nanocomposite catalyst for OER in alkaline media using a non-noble metal chelate polymer and a porous carbon. This method can be applied to the synthesis of transition metal oxide nanoparticles used in the preparation of composite electrodes for water electrolyzers and can be used to derive cathode materials for aqueous-type metal-air batteries.

Oxidation reactions on semiconducting metal oxides (SMOs) surfaces have been extensively worked on in catalysis, fuel cells, and sensors. SMOs engaged powerfully in energy-related applications such as batteries, supercapacitors, solid oxide fuel cells (SOFCs), and chemical gas sensors. The deep understanding of SMO surface and oxygen interactions and defect engineering has become significant because all those mentioned applications are based on the adsorption/absorption and consumption/transportation of adsorbed (physisorbed-chemisorbed) oxygen. More understanding of adsorbed oxygen and oxygen vacancies (〖V_O^•,V〗_O^(••)) is needed, as the former is the vital requirement for sensing chemical reactions, while the latter facilitates the replenishment of adsorbed oxygen ions on the surface. We determined the relation between sensor response (sensitivity) and the amounts of adsorbed oxygen ions (O_(2(ads))^-,O_((ads),)^- O_2(ads)^(2-),O_((ads))^(2-)), water/hydroxide groups (H2O/OH^-), oxygen vacancies (〖V_O^•,V〗_O^(••)), and ordinary lattice oxygen ions (O_lattice^(2-)) as a function of temperature. During hydrogen (H2) testing, the different oxidation states (W6+, W5+, and W4+) of WO3 were quantified and correlated with oxygen vacancy formation (〖V_O^•,V〗_O^(••)). We used a combined application of XPS, UPS, XPEEM-LEEM, and chemical, electrical and sensory analysis for H2 sensing. We established a correlation between the H2 sensing mechanism of WO3, sensor signal magnitude, the amount of adsorbed oxygen ions, and sensor testing temperature. This paper also provides a review of the detection, quantification, and identification of different adsorbed oxygen species. The different surface and bulk-sensitive characterization techniques relevant to analyzing the SMOs-based sensor are tabulated, providing the sensor designer with the chemical, physical, and electronic information extracted from each technique.

Addressing global environmental problem, water splitting to produce hydrogen fuel by solar energy is getting so much attention. In the water splitting, the essential problem to solve is the development of efficient　catalysts for oxygen production. In this paper, having the prospect for a practical application of photocatalysts to artificial photosynthesis, molecular mechanisms in the current literature are briefly reviewed. At first, recent progress in the function of Mn cluster at the natural photosystem II is briefly described. The kinds of devices in which oxygen evolution reaction (OER) catalysts are used were designated; water electrolyzers, photoelectrodes, and photocatalysts. Some methods for analyzing molecular mechanism in OER catalysis, emphasized by FTIR method, are shown briefly. After describing common OER mechanisms, the molecular mechanisms are discussed for TiO2 and BiVO4 photoelectrodes with our novel data, followed by presenting of co-catalysts IrO2, RuO2, NiO2, and other metal oxides for OER catalysts. Recent reports describing OER catalysts of perovskites, layered double hydroxides (LDH), metal-organic frameworks (MOF), single atom catalysts, as well as metal complexes are reviewed. Finally, by comparing with natural photosystem, the requiring factors to improve the activity of the catalysts for artificial photosynthesis will be discussed.

Novel 4-(diphenylphosphoryl)-1-phenylbutane-1,3-dione was synthesized by the reaction of diketone enamine with diphenylchloro phosphine followed by oxidation and hydrolysis of the enamine phosphine formed. Tautomeric transformation of the diketone moiety of phosphine oxide was investigated by ¹H NMR. Three out of five possible tautomers were observed in the 4-(diphenylphosphoryl)-1-phenylbutane-1,3-dione solution. The major tautomer was the form with a diketone fragment.

Nanostructured anodic oxide layers on an FeAl₃ intermetallic alloy were prepared by two-step anodization in 20 wt.% H2SO4 at 0°C. The voltage range was 10.0 – 22.5 V with a step of 2.5 V. The structural and morphological characterizations of the received anodic oxide layers were performed by FE-SEM. Therefore, the formed anodic oxide was found to be highly porous with a high surface area, as indicated by the FE-SEM studies. It has been shown that the morphology of fabricated nanoporous oxide layers is strongly affected by the anodization potential. The oxide growth rate first increased slowly (from 0.010 μm/s for 10 V to 0.02 μm/s for 15 V) and then very rapidly (from 0.04 μm/s for 17.5 V up to 0.13 μm/s for 22.5 V). The same trend was observed for the change in the oxide thickness. Moreover, for all investigated anodizing voltages, the structural features of the anodic oxide layers, such as the pore diameter and interpore distance, increase with increasing anodizing potential. The obtained anodic oxide layer was identified as a crystalline FeAl₂O₄, Fe₂O₃ and Al₂O₃ oxide mixture.

Inorganic chemistry has contributed to the progress of human civilization in several different ways. Its activities at the interface with other scientific disciplines has led to emergence of several new fields like organometallic chemistry, bio-inorganic chemistry, solid-state chemistry, environmental chemistry, etc. In the past few decades, it has made inroads in yet another dimension of immense relevance, i.e. nano-science and –technology. In this assay an attempt has been made to present an overview of utility of inorganic and organometallic compounds as precursors for the synthesis of nano-materials with reference to catalysis and materials science. Applications of metal nanoparticles (NPs) and metal chalcogenide NPs, generated through molecular precursor route, in catalysis have been discussed. Synthesis of ternary and quaternary metal chalcogenide nano-materials by molecular precursor route has been reviewed.

In this article, copper(II) oxide and titanium dioxide nanoparticles were added to Group III base oil formulated with 8 wt% Komad 323 dispersant. The nanoparticles were treated with ethyl oleate surface modification. The tribological properties of the homogenized oil samples were tested on a linear oscillating tribometer with continuous monitoring of static friction. Friction absolute integral values were calculated from high data acquisition. The wear was evaluated using a digital optical and confocal microscope. The wear types were characterized with scanning electron microscopy, while the remaining additives were located and quantified with energy-dispersive X-ray spectroscopy. The measurement results show that the CuO nanoparticles did not work well with the Komad 323 dispersant. As a result of their antagonistic effect, in the case of low CuO concentrations (≤0.3 wt%), the friction increased, while in the case of high concentrations (≥0.4%), surface fatigue caused a high wear rate. The cooperation between TiO2 and the dispersant showed synergistic effects. The oxygen-rich boundary layer formed on the worn surface with a titanium content of 0.33-0.39 norm.wt% provides both lower friction and high wear resistance.

Iron oxide nanoparticles have been investigated due to their suitable characteristics for diverse applications in the fields of biomedicine, electronics, water/wastewater treatment and sensors. Maghemite, magnetite and hematite are the most widely studied iron oxide particles and have ferrimagnetic characteristics. When very small, however, these particles have superparamagnetic properties and are called superparamagnetic iron oxide nanoparticles (SPIONs). Several methods are used for the production of these particles, such as coprecipitation, thermal decomposition and microemulsion. However, the variables of the different types of synthesis must be assessed to achieve greater control over the particles produced. In some studies, it is possible to compare the influence of variations in the factors for production with each of these methods. Thus, researchers use different adaptations of synthesis based on each objective and type of application. With coprecipitation, it is possible to obtain smaller, more uniform particles with adjustments in temperature, pH and the types of reagents used in the process. With thermal decomposition, greater control is needed over time, temperature as well as the proportion of surfactants and organic and aqueous phases in order to produce smaller particles and a narrower size distribution. With the microemulsion process, the control of the confinement of the micelles formed during synthesis through the proportions of surfactant and oil makes the final particles smaller and less dispersed. These nanoparticles can be used as additives for the creation of new materials, such as magnetic bacterial cellulose, which has different innovative applications. Composites that have SPIONs, which are produced with greater rigour with regards to size and distribution, have superparamagnetic properties and can be used in medical applications, whereas materials containing larger particles have ferromagnetic applications. To arrive at a particular particle with specific characteristics, researchers must be attentive to both the mechanism selected and the production variables to ensure greater quality and control of the materials produced.

The development and improvement of methods for the synthesis of environmentally friendly catalysts based on base metals is currently an urgent and promising task of modern catalysis. Catalysts based on nanoscale magnetite and maghemite have fast adsorption-desorption kinetics and high chemical activity. The purpose of this work was to obtain magnetic composites, determine their physicochemical characteristics and verify their activity in the process of liquid-phase oxidation of phenol with oxygen. Magnetic nanocomposites were obtained by chemical co-deposition of salts of ferrous and trivalent iron. The synthesized magnetic composites were studied by X-ray diffractometry, energy dispersive X-ray fluorescence and Mössbauer spectroscopy, IR-Fourier spectroscopy, elemental analysis. To increase the catalytic activity in oxidative processes, the magnetite surfaces were modified using cobalt nitrate salt. Further, CoFe2O4 was stabilized by adding polyethylenimine (PEI) as a surfactant. Preliminary studies of the oxidation of phenol with oxygen, as the most typical environmental pollutant were carried out on the obtained Fe3O4, CuFe2O4, CoFe2O4/PEI catalysts. The spectrum of the reaction product shows the presence of CH in the aromatic ring and double C=C bonds, stretching vibrations of the C=O groups of carbonyl compounds; the band at 3059 cm–1 corresponds to the presence of double C=C bonds, the band at 3424 cm–1 hydroquinone compounds. The band at 1678 cm–1 and the intense band at 1646 cm–1 refer to vibrations of the С=О bonds of the carbonyl group of benzoquinone. Peaks at 1366 cm–1 and 1310 cm–1 can be related to the vibrations of C–H and C–C bonds of the quinone ring. Thus it was demonstrated that produced magnetic composites based on iron oxide are quite effective in the oxidation of phenol with oxygen.

Road vehicles are a large contributor to Nitrogen Oxides (NOx) pollution. The routine road-side monitoring stations, however, may underrepresent the severity of personal exposure in urban areas, because long-term average readings cannot capture the effects of momentary, high peaks of air pollution. While numerical modelling tools historically have been used to propose an improved distribution of monitoring stations, ultra-high resolution Computational Fluid Dynamics models can further assist the relevant stakeholders in understanding the important details of pollutant dispersion and exposure at local level. This study deploys a 10 cm-resolution CFD model to evaluate actual high peaks of personal exposure to NOx from traffic, by tracking the gases emitted from the tailpipe of moving vehicles being dispersed towards the roadside. The investigation shows that a set of four Euro 5-rated diesel vehicles travelling at constant speed may generate momentary road-side concentrations of NOx as high as 1.25 mg/m3, with 25% expected increase for doubling the number of vehicles and approximately 50% reduction when considering Euro 6-rated vehicles. The paper demonstrates how the numerical tool can be used to identify the impact of measures to reduce personal exposure, such as protective urban furniture, as traffic patterns and environmental conditions change.

With the ever-growing geopolitical tensions across borders arising, ultimately from the eternal energy needs, it is the peak time for humanity to put its reliance on a more quasi-perpetuity source of energy, such as the Sun. Even though current photovoltaics are the frontier of solar power harvesting, their efficiencies are reaching a state of stasis sooner or later. The efficiencies of single-junction solar cells are capped by the Shockley-Quiesser limit of 33.7%. Researchers are racing toward a way to beat this limit while keeping the Levelized Cost of Energy (LCE) to its minimum. Amongst all contenders, rectenna (or rectifying antenna), which was invented only a decade after the first practical PV cell by the Bells lab [1], is the most promising technology to take the forefront in quenching the energy needs, not only because of the absence of any such theoretical limit but also a lower cost of production. This report will review three state-of-the-art architectures for optical rectification developed by the leading groups worldwide. The review will compile a concise discussion on Metal-Double-Insulator-Metal diodes, CNT-Insulator-Metal diodes, and Point-contact-Metal-Insulator-Metal diodes, with an elaborative focus on their fabrication methods and results obtained.

In this article, metallic additive manufacturing (AM) processes were classified and demonstrated. AM technology can be applied to a wide range of industrial areas because of its great feasibility in the design and manufacturing of various complex parts. The main factor that distinguishes various metallic AM processes from each other is the deposition method. Deposited metal can be imported in the form of melt or semi-solid. AM technology also covers a wide range of materials like aluminum, titanium, and many other alloys. Some of the common applications of metallic AM processes are the quick manufacturing of the parts which utilized in various industries like medical, automotive, aerospace, and jewelry industries. AM can help to fabricate parts that are impossible to be manufactured by other processes.

The surface configurations of the low-index facets of a set of spinel oxides are investigated using DFT+U calculations to derive surface energies and predict equilibrium nanoparticle shapes via the Wulff construction. Two very different conditions are investigated, corresponding to application either in heterogeneous catalysis or in electrocatalysis. First, the bare stoichiometric surfaces of NiFe₂O₄, CoFe₂O₄, NiCo₂O₄, ZnCo₂O₄ spinels are studied to model their use as high-temperature oxidation catalysts. Second, focusing attention on the electrochemical oxygen evolution reaction (OER), and on the CoFe₂O₄ inverse spinel as the most promising OER catalyst, we generate surface configurations by adsorbing OER intermediates, and, in an innovative study, we recalculate surface energies taking into account adsorption and environmental conditions, i.e., applied electrode potential and O₂ pressure. We predict that, under OER operating conditions, (111) facets are dominant in CoFe₂O₄ nanoparticle shapes, in fair agreement with microscopy measurements. Importantly, in the OER case we predict a strong dependence of nanoparticle shape upon O₂ pressure. Increasing O₂ pressure increases the size of the higher-index (111) and (110) facets at the expense of the (001) more catalytically active facet, whereas the opposite occurs at low O₂ pressure. These predictions should be experimentally verifiable and help define the optimal OER operative conditions.

For thermoelectric materials study and development, it is very important to measure the electrical power and efficiency of a thermoelectric generator (TEG). In this study, thermoelectric properties such as electrical conductivity, Seebeck coefficient, and thermal conductivity of cement composites with graphene nanoplatelets and metallic oxides (Fe2O3, ZnO, MnO2) are measured and subsequently used to figure out the output electrical power and efficiency. A maximum of 1.5 W power per square meter for a temperature difference of about 50 °C can be estimated using GnP-ZnO added cement composites. This paper also talks about how to make a cement composite-based structural TEG module to enhance the total output voltage, power, and efficiency of the system.

Currently, the use of sustainable chemistry as an ecological alternative for the generation of products or processes, free of polluting substance has assumed a preponderant role. The aim of this work is propose a bioinspired, facile, at low cost, non-toxic and environmentally friendly alternative to obtaining magnetic nanoparticles whit a majority phase of magnetite (Fe₃O₄). Is important to empathize that the synthesis was based on the chemical reduction through the Cnicus Benedictus extract, whose use as reducing agent has not been reported in the synthesis of iron oxides nanoparticles. In addition, the Cnicus Benedictus is abundant endemic plant in Mexico, with several medicinal properties and a large number of natural antioxidants. The obtained nanoparticles exhibited significant magnetic and antibacterial properties and an enhanced photocatalytic activity. The crystallite size of the Fe₃O₄ nanoparticles (Fe₃O₄ NP’s) was calculated by Williamson-Hall method. The photocatalytic properties of the Fe₃O₄ NP´s were studied by kinetics absorptions models in the Congo red (CR) degradation. Finally the antibacterial effect of the Fe3O4 NP´s were evaluated mediated the Kirby-Bauer method against E. coli and S. aureus bacteria. This route offers a green alternative to obtain Fe3O4 NP´s with remarkable magnetic, photocatalytic and antibacterial properties.

Novel Ca3(BTC)2 metal-organic frameworks with different sizes and shapes constructed by Ca2+ and trimesic acid as metal center and ligands respectively were synthesized by a surfactant-assisted method. The relationship between the quantity of surfactant and the particle morphology of the product have been further studied. The samples were characterized by scanning electron microscope, powder X-ray diffraction and Inductively coupled plasma mass spectrometry. The results indicated that the size and shape of Ca3(BTC)2 could be regulated by changing the quantity of surfactant. Rod- and sheet-like Ca3(BTC)2 MOFs have been readily availabled. The removal kinetics of heavy metals of Pb(II) were also studied by rod-like Ca3(BTC)2. The results showed that as-synthesized Ca3(BTC)2 could effectively remove heavy metals of Pb(II) from the sewage.

Dimers and oligomers of alkenes represent a category of compounds that are in great demand for diverse industrial sectors. Among the developing synthetic methods, the catalysis of alkene dimerization and oligomerization using transition metal salts and complexes is of undoubted interest for practical application. This approach demonstrates substantial potential, offering not only elevated reaction rates but also precise control over the chemo-, regio-, and stereoselectivity of the reactions. In this review, we discuss the data on catalytic systems for alkene dimerization and oligomerization. Our focus lies in the analysis of how the activity and chemoselectivity of these catalytic systems are influenced by various factors, such as the nature of the transition metal, the ligand environment, the activator, and substrate structure. Notably, the review particularly discusses the reaction mechanisms, encompassing metal complex activation, structural and dynamic features, and the reactivity of hydride intermediates, which serve as potential catalytically active centers in alkene dimerization and oligomerization.

Metal/metal composites represent a particular class of materials showing innovative mechanical and electrical properties. Conventionally, such materials are produced by severely plastically deforming two ductile phases via rolling or extruding, swaging, and wire drawing. This study presents the feasibility of producing metal/metal composites via a capacitive discharge-assisted sintering process named electro-sinter-forging. Two different metal/metal composites with CP-Ti/AlSi10Mg ratios (20/80 and 80/20 %vol) are evaluated, and the effects of the starting compositions on the microstructural and compositional properties of the materials are presented. Bi-phasic metal/metal composites constituted by isolated α-Ti and AlSi10Mg domains with a microhardness of 113 ± 13 HV_0.025 for the Ti20-AlSi and 244 ± 35 HV_0.025 for the Ti80-AlSi are produced. The effect of the applied current is crucial to obtain high theoretical density, but too high currents may result in Ti dissolution in the Ti80-AlSi composite. Massive phase transformations due to the formation of AlTiSi based intermetallic compounds are observed through thermal analysis and confirmed by morphological and compositional observation. Finally, a possible explanation for the mechanisms regulating densification is proposed accounting for current and pressure synergistic effects.

Herein, a novel cavity design of racetrack integrated circular cavity established on metal-insulator-metal (MIM) waveguide is suggested for refractive index sensing application. Over the past few years, we have witnessed several unique cavity designs to improve the sensing performance of the plasmonic sensors created on the MIM waveguide. The optimized cavity design can provide the best sensing performance. In this work, we have numerically analyzed the device design by utilizing the finite element method (FEM). The small variations in the geometric parameter of the device can bring a significant shift in the sensitivity and FOM of the device. The best sensitivity and FOM of the anticipated device are 1400 nm/RIU and ~12.01, respectively. We believe that the sensor design analyzed in this work can be utilized in the on-chip detection of biochemical analytes.

In a constantly changing environment brought about by the climate crisis and escalated anthropogenic perturbations driven by the growing population, harmful algal bloom dynamics and their impacts are expected to shift, necessitating adaptive management strategies and comprehensive research efforts. Similar to primary productivity, HABs have been thought to be driven primarily by major nutrients such as N, P, and Si. However, recent investigations on the role and importance of micronutrients as limiting factors in aquatic environments have been highlighted. This paper provides a review of metal and phytoplankton interactions, with a specific emphasis on pertinent information on the influence of trace nutrients on growth, toxin production, and other underlying mechanisms related to the dynamics of HABs. Low to near-depleted levels of essential nutrients including Fe, Cu, Zn, Se, Mn, Co, and Mo, negatively impact cell growth and proliferation of various marine and freshwater HAB species. However, evidence shows that at elevated levels, these trace elements along with other non-essential ones, could still cause toxic effects to certain HAB species manifested by decreased photosynthetic activities, oxidative stress, ultrastructure damage, and cyst formation. Interestingly, while elevated levels of these metals mostly result in increased toxin production, Co (i.e., yessotoxins, gymnodimine, and palytoxins) and Mn (i.e., isodomoic acid, okadaic and diol esters) enrichments revealed otherwise. In addition to toxin production, releasing dissolved organic matter (DOM) including dissolved organic carbon (DOC) and humic substances was observed as an adaptation strategy, since these organic compounds have been proven to chelate metals in the water column, thereby reducing metal-induced toxicity. Whilst current research center on free metal toxicity of specific essential elements such as in Cu and Zn, a comprehensive account of how trace metals contribute to the growth, toxin production, and other metabolic processes under conditions reflective of in-situ scenarios of HAB-prone areas, would yield new perspectives on the roles of trace metals in HABs. With the growing demands of the global population for food security and sustainability, substantial pressure is exerted on the agriculture and aquaculture sector, highlighting the need for effective communication of information regarding the interactions of macro- and micronutrients with HABs to improve existing policies and practices.

Electroless etching of semiconductors was elevated to an advanced micromachining process by the addition of a structured metal catalyst. Patterning of the catalyst by lithographic techniques facilitates the patterning of crystalline and polycrystalline wafer substrates. Galvanic deposition of metals on semiconductors has a natural tendency to produce nanoparticles rather than flat uniform films. This characteristic makes possible the etching of not only wafers but also particles with arbitrary shape. While it has been widely recognized that spontaneous deposition of metal nanoparticles can be used in connection with etching to porosify wafers, it is also possible to produced nanostructured powders. MACE can be controlled to produce (1) etch track pores with shapes and sizes closely related to the shape and size of the metal nanoparticle, (2) hierarchically porosified substrates exhibiting combinations of large etch track pores and mesopores, and (3) nanowires with either solid or mesoporous cores. This review discussed the mechanisms of porosification, processing advances and the properties of the etch product with special emphasis on the etching of silicon powders.

Serum transferrin (sTf) plays a pivotal role in regulating iron biodistribution and homeostasis within the body. The molecular details of sTf Fe(III) binding, blood transport, and cellular delivery through transferrin receptor-mediated endocytosis are generally well-understood. Emerging interest exists in exploring sTf complexation of nonferric metals as it facilitates the therapeutic potential and toxicity of several of them. This review explores recent X-ray structural and physiologically relevant metal speciation studies to understand how sTf partakes in the bioactivity of key non-redox active hard Lewis acidic metals. It challenges preconceived notions of sTf structure function correlations that were based exclusively on the Fe(III) model by revealing distinct coordination modalities that nonferric metal ions can adopt and different modes of binding to metal-free and Fe(III)-bound sTf that can directly influence how they enter into cells and, ultimately, how they may impact human health. This knowledge informs on biomedical strategies to engineer sTf as a delivery vehicle for metal-based diagnostic and therapeutic agents in the cancer field. It is the intention of this work to open new avenues for characterizing the functionality and medical utility of nonferric-bound sTf and to expand the significance of this protein in the context of bioinorganic chemistry.

Catalytic studies for hydrogen production via steam reforming of ethanol (SRE) are essential for process optimization. Likewise, selecting the ideal support for the active phase can be critical to achieve high conversion rates during the catalytic steam reforming. In this work, copper-based catalysts were synthesized using two different supports, NaY zeolite and Nb2O5/Al2O3 mixed oxides. The materials were prepared using wet impregnation and characterized for their physicochemical properties using different analytical techniques. Differences in catalyst morphologies were readily attributed to the characteristics of the support. The Cu/NaY catalyst showed better textural properties than Cu/Nb2O5/Al2O3, resulting in a homogeneous metal dispersion over the support surface. Both catalytic systems were active in SRE, but Cu/NaY resulted in higher ethanol conversions compared to Cu/Nb2O5/Al2O3. Hence, the performance of copper-based catalysts was influenced significantly by the textural properties of the support.

This study aimed to develop multifunctional nanoplatforms for both cancer imaging and therapy using superparamagnetic iron oxide nanoparticles (SPIONs). Two distinct synthetic methods, reduction-precipitation (MR/P) and co-precipitation at controlled pH (MpH), were explored, including the assessment of coating’s influence, namely dextran and gold, on their magnetic properties. These SPIONs were further functionalized with gadolinium to act as dual T1/T2 contrast agents for magnetic resonance imaging (MRI). Parameters such as size, stability, morphology, and magnetic behavior were evaluated by a detailed characterization analysis. To assess their efficacy in imaging and therapy, relaxivity and hyperthermia experiments were performed, respectively. The results revealed that both synthetic methods lead to SPIONs with similar average, 9 nm. Mössbauer spectroscopy indicated that samples obtained from MR/P consist of approximately 11-13% of Fe present in magnetite, while samples obtained from MpH have higher content, of 33%-45%. Despite coating and functionalization, all samples exhibited superparamagnetic behavior at room temperature. Hyperthermia experiments showed increased SAR values with higher magnetic field intensity and frequency. Moreover, the relaxivity studies suggested potential dual T1/T2 contrast agent capabilities for the coated SPpH-Dx-Au-Gd sample, thus demonstrating its potential in cancer diagnosis.

Using density functional theory (DFT), the density of states of NH4V3O8 (NVO) was analyzed pre and post-oxygen defects (Od) formation. The findings revealed a reduced bandgap in NVO after Od introduction, emphasizing the role of Od in enhancing conductivity of the material, thus improving its electrochemical attributes. Through the water bath method, both NVO and its oxygen-deficient counterpart, (NH4)2V10O25⸱8H2O (NVOd), were synthesized as potential cathode materials for aqueous zinc-ion batteries (AZIBs). Experimental outcomes resonated with DFT predictions, highlighting the beneficial role of oxygen defects in boosting electrical conductivity. Notably, the refined material displayed a remarkable capacity of 479.3 mAh g-1 at 0.1 A g-1, underscoring its promise for advanced energy storage solutions.

The cast defects strongly degrade the mechanical properties in cast alloys. The effect of Sn addition on Al-Si alloys was investigated by 3D computed tomography, SEM and TEM. Amorphous Sn oxides are found near the alumina film, cause more shrinkage pores, initiate cracks and deteriorate mechanical properties. This work suggests not adding Sn in various Al alloys used in cast state.

The presence of copper in distilled sugar cane spirits, especially cachaça produced in alembics, has impeded the marketing of this product. Red mud (RM) is a residue obtained from alumina production. It contains a high concentration of metal oxides and is very alkaline. The RM was dried at 100 oC and sifted through a 150-micron sieve. The sample was characterized by B.E.T. nitrogen adsorption, scanning electron microscopy-energy-dispersive X-ray (SEM-EDX) and Atomic Absorption Spectrometry (A.A.S.). The textural parameters indicate that the total surface area (S.T.) was 21.9 m2g-1, and the total volume pore (V.T.) was 0.09 cm3g-1. The RM (1 g) was stirred for two hours with a 1.0 L cachaça sample containing 9.39 mg of copper L-1 and filtered under atmospheric pressure. The concentration of copper ions detected in the filtrate was 0.00 mg L-1. No copper ions were retained when the cachaça was filtered through the RM under high pressure without stirring prior to filtration.

This article will briefly review the progress of h-BN based solid-state metal semiconductor metal (MSM) neutron detectors. In the last decade, several groups have been working on hexagonal boron nitride (h-BN) based solid-state neutron detectors. Recently, the detection efficiency of 59% has been reported. Efficient, low-cost neutron detectors made from readily available materials are essential for various applications. Neutron detectors are widely used to detect fissile materials and nuclear power plants for security applications. The most common and widely used neutron detectors are 3He based, which are sometimes bulky, difficult to transport, have high absorption length, need relatively high bias voltage (>1000 V), and have low Q-value (0.764 MeV). Also, 3He is not readily available material. Thus, there is a strong need to find an alternative detection material. 10B isotope has a high neutron absorption cross-section, and it has been tested as a coating on the semiconducting materials. Due to the two-step process, neutron capture through 10B, and then electron-hole pair generation in a typical semiconducting material, the efficiency of these devices is not up to the mark. The progress in h-BN based detectors requires a review to envision the further improvement in this technology.

Using two metal insulated metal waveguides (MIM) and five resonator (a quadrilateral cavity and three rings with different dimensions), we design a plasmonic refractive index sensor. Using the time domain finite difference method, we examine and analyze the sensor performance (numerical analysis) and using the transmission line model method, we theoretically examine the performance of the sensor By summarizing these two methods and calculating the sensitivity coefficient S, quality coefficient Q and figure of merit (FOM), a plasmonic sensor with good performance is obtained. Using the supermods of the resonators, we will achieve a stable wavelength spectrum and a suitable and stable sensitivity coefficient spectrum. Challenges and changes that occur in different modes of this sensor will lead to a balanced and relatively good structure. This designed sensor can be useful in the development of integrated optical circuits.

In this paper, a plasmonic refractive index sensor based on metal insulated metal waveguide (MIM) with three rings and a resonant cavity is first proposed and numerically evaluated. Next, we add four teeth to the sensor structure. We study and simulate the resonant wavelengths and refractive index of resonators using the time difference finite difference method. Given that the sensor and the conduction characteristics of plasmonic waves are influenced by the structure parameters,Therefore, by changing the refractive index and changing the dimensions and coordinates of the cavity and rims, we can change the passage coefficient in the resonant modes and measure the sensor performance. As a result, we obtain the sensitivity coefficient, the figure of merit (FOM) and the quality factor Q of the sensor. We modulate the resonance wavelength FWHM using the generated modes and reach a sensitivity of 2166 nm / RIU. These plasmonic sensors with a simple framework and balanced performance and high optical resolution can be used to measure the refractive index in the medical, chemical and food industries.

In this study, we seek to analyze and numerically evaluate a plasmonic sensor. To form the sensor structure, we use several amplifiers, such as two rings attached to each other and a cavity, as well as two metal insulating metal waveguides (MIM). At the beginning of this simulation, we must examine the resonant wavelengths and the refractive index of the resonators using the finite difference time domain method. By changing the refractive index and changing the dimensions of the cavity and the rims, we seek to investigate the sensor performance and the conduction characteristics of the plasmonics and to obtain the effect of these parameters. To evaluate the sensor performance, we calculate the three factors of sensitivity coefficient S, quality factor Q and figure of merit (FOM), here we reach the sensitivity of 987.6 nm / RIU. Such a plasmonic sensor with a simple framework and high optical resolution can be very useful for sensor systems on optical circuits.

Metal additive manufacturing (AM) has gained much attentions in recent years due to its advantages including geometric freedom and design complexity, appropriate to a wide range of potential industrial applications. However, conventional metal AM methods have high-cost barriers due to the initial cost of the capital equipment, support and maintenance, etc. This study presents a unique low-cost metal material extrusion (MME) technology. The filaments used have polylactic acid (PLA) as the matrix and metal powders (copper, bronze, stainless steel, high carbon iron, and aluminum) as reinforcements. Using the proposed fabrication technology, test specimens were built by extruding polymer/metal composite filaments, which were then sintered in an open-air furnace to produce solid metallic parts. In this research, the mechanical and thermal properties of the built parts are examined using tensile tests, thermogravimetric-, thermomechanical- and microstructural analysis.

This study investigates the influence of adding hydrogen as an additive to gasoline in a four-stroke engine, utilizing a comprehensive thermodynamic comparative analysis conducted with self-developed engine model. The research aims to assess the performance, emissions, and efficiency of the engine when using gasoline-hydrogen blends, and to provide insights into the potential benefits of this approach. First the engine performance and emissions under different hydrogen blending levels were examined. A range of different air-to-fuel ratios (rich to lean) and varying percentages of hydrogen were considered. This systematic variation allowed for a detailed evaluation of the influence of hydrogen content on combustion efficiency, power out-put, and emissions characteristics. The analysis results included key parameters such as indicated specific fuel consumption and mean effective pressure. Additionally, the study focused on range prediction of nitrogen oxides (NOx) emissions, which are a critical environmental concern asso-ciated with internal combustion engines. The analysis of pressure and temperature profiles throughout the engine cycle shed light on the combustion characteristics and efficiency im-provements associated with hydrogen addition. In terms of emissions, the study projected that all emissions were reduced except NOx, which is highly dependent on hydrogen percentage, and it might be reduced in some cases, but with higher temperatures and pressures associated with hydrogen addition in most cases there is actually NOx increase, especially at higher engine loads.

Metals are particularly sensitive to some pollutant gases. Many museum showcases and store rooms present atmospheres that can corrode cultural heritage artefacts containing metals. Whilst numerous strategies have been reported to mitigate such situations, avoiding them is preferable. Several approaches to testing materials used in construction, fitting out or dressing are used. The relative merits and drawbacks will be discussed. Several parameters of the most widely used, the accelerated corrosion ‘Oddy’ test have been investigated. The influence of abrasive on subsequent corrosion of lead and copper coupons have been assessed. Quantification methods for tested coupons are reviewed. The influence of test duration and temperature were assessed through comparison with real life, long term experience of materials behaviour. Direct contact tests with the material tested touching the test material has been investigated. Several materials present in artefacts are known to potentially cause corrosion when enclosed with metals in other artefacts. A number of situations have been investigated with pollution and RH and some corrosion rate measurements. Ways to isolate artefacts or mitigate are explored and a decision support model has been developed.

This research was conducted to analyze the content of Fe, Cu, Cd, Cr, and Pb in several species of fish taken from three lakes that is closely to disposal of industrial waste in Indonesia. The fish samples were taken from three lakes, namely, Muara Angke, Weda, and Morowali. The samples from Morowali were analyzed in April 2019, those from Weda from November to December 2019, and those from Muara Angke in June 2018. All the samples were then analyzed at the chemistry laboratory of the Department of Chemistry, Faculty of Mathematics and Natural Science, University of Indonesia, and the Integrated Laboratory of IPB. The results showed that all types of fish from Morowali and Weda were no longer safe to consume because they contained Fe, Cu, Cd, and Cr exceeding the threshold of metal contamination. Meanwhile, all types of fish from Muara Angke, except for ayam-ayam, are still safe for consumption. The results of this study can be a source of information regarding metal content in fish and fish feed for safe consumption. Several studies have been done to determine the metal pollutants contained by fish. Given the high consumption rate of fish and the hazards of heavy metals on humans’ health, such research must be furthered

Gasca D herbal formulation is an antidiabetic medicine for the management of diabetes mellitus produced exclusively from natural ingredients. The level of some essential elements (Copper, chromium, Cobalt, Iron, Manganese, Nickel and zinc) and toxic (Cadmium, Arsenic, Mercury, and Lead) heavy metals were determined using microwave plasma-atomic emission spectrometry (MP-AES). The aim of this study is to evaluate the levels of essential and toxic heavy metals and also identify bioactive compounds present in Gasca D herbal formulation. The result shows no traces of Lead, Mercury, Zinc, Arsenic and Zinc, Iron was found to have highest concentration 67.16 + 7.5 µg/g and Cadmium lowest concentration 0.4 + 0.03µg/g. GC-MS analysis of Gasca D herbal formulation revealed the presence of 14 biologically active compounds which include N-Formyl-beta-alanine, Paromomycin, 3,4-Altrosan, Benzamide, 1,3,4-Thiadiazol-2-amine, Carbamodithioic acid, Carbonic acid, alpha-D-Glucopyranoside, Ethyl isocyanide, 2-Propanesulfinic acid, Propanamide, 2-Butenenitrile, Dicyclopropyl carbinol, Isoxazolidine, 1,5-Hexadiene 10-Azido-1-decanethiol. Conclusion: The result indicates that the mean levels of toxic metals in Gasca D herbal formulation were below WHO permissible levels. Gasca D herbal formulation also contains various bioactive compounds that can have various medicinal application which can be used for the treatment of various diseases.

Based upon Maxwell's equations, it has long been established that oscillating electromagnetic (EM) fields incident upon a metal surface decay exponentially inside the conductor, leading to a virtual EM vacuum at sufficient depths. Magnetic resonance imaging (MRI) utilizes radiofrequency (r.f.) EM fields to produce images. Here we present the first visualization of a virtual EM vacuum inside a bulk metal strip by MRI, amongst several novel findings. We uncover unexpected MRI intensity patterns arising from two orthogonal pairs of faces of a metal strip, and derive formulae for their intensity ratios, revealing differing effective elemental volumes (voxels) underneath these faces. Further, we furnish chemical shift imaging (CSI) results that discriminate different faces (surfaces) of a metal block according to their distinct nuclear magnetic resonance (NMR) chemical shifts, which holds much promise for monitoring surface chemical reactions noninvasively. Bulk metals are ubiquitous, and MRI is a premier noninvasive diagnostic tool. Combining the two, the emerging field of bulk metal MRI can be expected to grow in importance. The fundamental nature of results presented here may impact bulk metal MRI and CSI across many fields.

The cutting-edge photovoltaic cells are an indispensable part of the ongoing progress of earth-friendly plans for daily life energy consumption. However, the continuous electrical demand that extends to the night time requires a prior deployment of efficient real-time storage systems. In this regard, metal-air batteries have presented themselves as the most suitable candidates for solar energy storage, combining extra lightweight with higher power outputs and promises of longer life cycles. Scientific research over non-precious functional catalysts has always been the milestone and still contributing significantly to exploring new advanced materials and moderating the cost of both complementary technologies. Metal-organic frameworks (MOFs) derived functional materials have found their way to the application as storage and conversion materials, owing to their structural variety, porous advantages, as well as the tunability and high reactivity. In this review, we provide a detailed overview of the latest progress of MOF-based materials operating in metal-air batteries and photovoltaic cells.

A useful and increasingly common additive manufacturing (AM) process is the selective laser melting (SLM) or direct metal laser sintering (DMLS) process. SLM/DMLS can produce full-density metal parts from difficult materials, but it tends to suffer from severe residual stresses introduced during processing. This limits the usefulness and applicability of the process, particularly in the fabrication of parts with delicate overhanging and protruding features. The purpose of this study was to examine the current insight and progress made toward understanding and eliminating the problem in overhanging and protruding structures. To accomplish this, a survey of literature was undertaken, focusing on process modeling (general, heat transfer, stress and distortion, and material models), direct process control (input and environmental control, hardware-in-the-loop monitoring, parameter optimization, and post-processing), experiment development (methods for evaluation, optical and mechanical process monitoring, imaging, and design-of-experiments), support structure optimization, and overhang feature design; approximately 140 published works were examined. The major findings of this study were that a small minority of the literature on SLM/DMLS deals explicitly with the overhanging stress problem, but some fundamental work has been done on the problem. Implications, needs, and potential future research directions are discussed in-depth in light of the present review.

Gaseous air pollutants emitted from anthropogenic sources are diverse and form secondary products through photochemical reactions, complicating the regulatory analysis of anthropogenic emissions in the atmosphere. Here, we used an environmental chassis dynamometer and a photochemical smog chamber to conduct a parameter sensitivity experiment to investigate the formation of secondary products from a direct-injection gasoline passenger car. To simulate the mitigation of ammonia (NH3) emissions from gasoline vehicle exhausts assuming future emission controls and to allow photochemical oxidation and aging of the vehicle exhaust, NH3 was selectively removed by a series of five denuders installed between the vehicle and the photochemical smog chamber. Overall, there were no differences in the formation of secondary organic aerosols and ozone with or without NH3 mitigation. However, the secondary particle formation potential of ammonium nitrate (NH4NO3) was significantly reduced with NH3 mitigation. In addition, NH3 mitigation resulted in increased particle phase acidity due to HNO3 in the gas phase not being neutralized by NH3 and condensing onto the liquid particle phase, indicating a potentially important secondary effect associated with NH3 mitigation. The present study provides new insights into the effects of NH3 mitigation on secondary emissions from gasoline vehicle exhaust and the experimental approach.

A La2FeCrO6 (LFCO) double perovskite powders were synthesized by hydrothermal method, which crystallized in an orthorhombic (Pnma) structure and exhibited a spherical morphology with average particle size of 900 nm. Fourier transformation infrared spectroscopy confirmed the octahedral coordination of Fe and Cr ions in the powders. XPS spectra revealed dual oxide states of Fe (Fe2+/Fe3+) and Cr (Cr3+/Cr4+) elements, and oxygen element appeared as lattice oxygen and defect oxygen, respectively. The LFCO powders exhibit ferromagnetic behavior at 5 K with saturation magnetization of 0.31 μB/f.u., coercive field of 8.0 kOe, and Curie temperature of 200 K. Griffiths phase appeared in the powders between 200 K and 223 K. The LFCO ceramics displayed a butterfly-like magnetoresistance (MR)-magnetic field (H) curve at 5 K with MR (5 K, 6 T) value of -4.07%. Temperature dependence of resistivity of the LFCO ceramics demonstrated their semiconducting nature. Electrical transport data were fitted by different conduction models. Strong frequency dispersion dielectric behavior was observed in the LFCO ceramics. A dielectric abnormality observed around 260 K, was ascribed to the jumping of electrons trapped in shallow levels created by oxygen vacancies. The dielectric relaxation behavior exhibited by dielectric loss between 160 K and 260 K, was contributed to the singly-ionized oxygen vacancies.

The article continues the search for a general law that describes the physical properties of a solid body, represented as a complex compound, through the physical properties of its elements. For a set of mixtures of metal oxides (actinide oxides), their melting or solidification temperatures were described in terms of the atomic weighted sum of the melting/solidification temperatures of these metals and molecular oxygen, multiplied by a variable which depending on the crystal structure and properties of melt of the compound and on the atomic numbers of the elements that make up the compound.

Lithium rich layered oxides (LRLO) are a wide class of innovative active materials for positive electrodes in lithium-ion (LIB) and lithium-metal secondary batteries (LMB). LRLOs are over-stoichiometric layered oxides rich in lithium and manganese, with general formula Li1+xTM1-xO2, where TM is a blend of transition metals comprising Mn (main constituent), Ni, Co, Fe and others. Due to the very variable composition and the extended defectivity their structural identity is still debated among researchers being likely an unresolved hybrid between a monoclinic (mC24) and a hexagonal lattice (hR12). Once casted in composite positive electrode films and assembled in LIBs or LMBs, LRLOs can delivery reversible specific capacities above 220-240 mAhg-1, thus beyond any other available intercalation cathode material for LIBs, with mean working potential above 3.3-3.4 V vs Li for hundreds of cycles in liquid aprotic commercial electrodes. In this review we critically outline the recent advancements in the fundamental understanding of the physico-chemical properties of LRLO as well as the most exciting innovations in their battery performance. We focus in particular on the elusive structural identity of these phases, on the complexity of the reaction mechanism in batteries as well as on practical strategies to minimize or remove cobalt from the lattice while preserving the outstanding performance upon cycling.

The aim of this work is to compare two softwares (MAUD and TOPAS) based on the Rietveld algorithm and to test the concept of tolerance factor using the dissolution at high temperature of yttrium into BaTiO₃. In general, both softwares give up different values of the crystalline parameters however the trends are similar in most cases but the analysis of the strain and crystallite size in the BaTiO₃ crystals suggests that, in this particular case, MAUD offered results more consistent with the expected behavior. Using the crystalline parameters calculated by Rietveld, the tolerance factor values were obtained and these data suggest even better stability in the crystalline structure than that expected using theoretical parameters. Tolerance factor concept also indicates that Ti⁴⁺ should be preferred.

Composite polymolecular separation membranes were prepared by combining multi-branched ZIF-L with high porosity electrospinning nanofibers PI. Meanwhile, PDA and PEI were introduced into the membrane in order to improve its adhesion. The new membrane is so called “PI@PDA@PEI/ZIF-L-4” composite membrane; compared with PI@PDA@PEI/ZIF-8 composite membrane, the new membrane’s filtration rates for heavy metal ions such as Cd2+, Cr3+ and Pb2+ were increased by 7.0%, 6.6% and 9.3%, respectively. Furthermore, the new membrane has a permeability up to 1,140.0 L·m−2·h−1·bar−1, and were presenting a very stable performances after four repeated uses. The separation mechanism of PI@PDA@PEI/ZIF-L composite membranes was further analyzed in order to provide a base support for producing separation membranes with high barrier rate and high flux.

The transferability of structure-property relationships for laser-pretreated metal adhesive joints to laser-pretreated metal – carbon fiber reinforced plastic (CFRP) bonds is investigated. Single-lap shear tests were performed on hybrid AW 6082-T6 – CFRP specimens pretreated with the same pulsed laser surface parameter sets on the metal surface as previously tested AW 6082-T6 – E320 metal adhesive joints. The fracture surfaces were characterized to determine the type of failure and elucidate differences and commonalities in the link between surface structures and single-lap shear strengths. Digital image analyses of the hybrid specimens fractured surfaces were used to quantify remaining CFRP fragments on the metallic joint side. The results indicate that high surface enlargements and the presence of undercut structures leads to single-lap shear strengths exceeding 40 MPa and 35 MPa for unaged and aged hybrid specimens respectively. While for the metal-polymer joints the trend from high strength to weakly bonded specimens was largely continuous with the degree of surface structuring, hybrid metal – CFRP joints exhibit a drastic drop in joint performance after aging if the laser-generated surface structures are less pronounced with low surface enlargements and crater depths. Surface features and hydrothermal aging determine whether the specimens fail cohesively or adhesively.

In this study, long-term mortality effects associated with exposure to PM10, PM2.5, BC (black carbon), and NOx were analyzed in a cohort in southern Sweden during the period from 1991‒2016. Participants (those residing in Malmö, Sweden, born between 1923‒1950) were randomly recruited from 1991‒1996. At enrollment, 30,438 participants underwent a health screening, which consisted of questionnaires about lifestyle and diet, a clinical examination, and blood sampling. Mortality data were retrieved from the Swedish national cause of death register. The modeled concentrations of PM10 (particles with an aerodynamic diameter smaller than or equal to 10 µm), PM2.5 (particles with an aerodynamic diameter smaller than or equal to 2.5 µm), BC (black carbon), and NOx (nitrogen oxides) at the cohort participants' home addresses were used to assess air pollution exposure. Cox proportional hazard models were used to estimate the associations between long-term exposure to PM10, PM2.5, BC, and NOx and the time until death among the participants during the period from 1991‒2016. The hazard ratios (HRs) associated with an interquartile range (IQR) increase in each air pollutant were calculated based on the exposure lag windows of the same year (lag0), 1‒5 years (lag1‒5), and 6‒10 years (lag6‒10). Three models were used with varying adjustments for possible confounders including both single-pollutant estimates and two-pollutant estimates. With adjustments for all covariates, the HRs for PM10, PM2.5, BC, and NOx in the single-pollutant models at lag1‒5 were 1.06 (95% CI: 1.02‒1.11), 1.01 (95% CI: 0.95‒1.08), 1.07 (95% CI: 1.04‒1.11), and 1.11 (95% CI: 1.07‒1.16) per IQR increase, respectively. The HRs were in most cases decreased by the inclusion of a larger number of covariates in the models. The most robust associations were shown for NOx, with statistically significant positive HRs in all models. An overall conclusion is that road traffic-related pollutants had a significant association with mortality in the cohort.

Breakthrough curves for the adsorption of H2S using a metal-oxides mixture were predicted using the Bohart-Adams model of fixed bed adsorption. This mixture (ZnMn2O4+ZnO+Mn2O3) came from the processing of an urban waste as spent alkaline batteries were. The H2S adsorption experiments were carried out in a fixed-bed column at 20º C, and under various experimental conditions: gas flow rate, inlet H2S concentration and adsorbent dosage. Curves predicted by the model matched well with experimental data, providing data for the possible scale-up of the system. At the various experimental variables, the efficiency of the column, were also provided in the work. This investigation demonstrated the usefulness of a waste material, like spent alkaline batteries, to provide an adsorbent material to mitigate the problem of the presence of this harmful gas.

First of all the paper presents a solid solution of piezoelectric ceramic that was synthesized according to the general formula Pb(1-x)Srx(Ti0.48Zr0.52)(1-y)NbyO3 with x = 0.05 and y = 0.02, using wet ceramic processing technology and using an oxide mix as prime material. The effects of dopants (Sr2+ and Nb5+) on phase constitution, on microstructure and on the dielectric and piezoelectric properties were determinate. The Zr/Ti ratio was chosen near the morphotropic phase boundary of the PZT system in studied composition. The XRD data revealed that the PZT doped composition had tetragonal perovskite structure. Secondly the paper presents the design of the novel piezo-motor based on a surface wave which translates the linear extension of different piezoelectric segments of a piezoelectric cylinder into a rotational bending movement. This rotational bending of the piezoelectric cylinder is then transformed into a continuous rotation of the rotor through a calculated contact. The design of the motor takes advantage of the high piezoelectric constants of the developed material in an optimal way in order to increase the energetic efficiency. A brief mathematical model of electromechanical answer of piezoelectric materials is presented as it was used in the modeling of the material during the numerical simulations.

Peptides, both natural and synthetic, are well suited for a wide range of purposes and offer versa-tile applications in different fields such as biocatalysts, injectable hydrogels, tumor treatment, and drug delivery. The rising prominence of therapeutic peptides encompasses anticancer, antiviral, antimicrobial, and anti-neurodegenerative properties. The metals Na, K, Mg, Ca, Fe, Mn, Co, Cu, Zn, and Mo are ten of the twenty elements that are considered essential for life. Crucial for under-standing the biological role of metals is the exploration of metal-bound proteins and peptides. Aside from essential metals, there are other, non-essential metals that also interact biologically, exhibiting either therapeutic or toxic effects. Irregularities in metal binding contribute to diseases like Alzheimer’s, neurodegenerative disorders, Wilson's, and Menkes disease. Certain metal com-plexes have potential applications as radiopharmaceuticals. The examination of these complexes was done by preforming UV-Vis, IR, EPR, NMR spectroscopy, and X-ray analysis.

We studied surface enhanced Raman spectra of amino acids D-alanine and DL-serine and their mixture on silver nanoisland films (SNF), immersed in phosphate buffer saline solution at millimolar amino acid concentrations. It is shown that the spectra from the amino acid solutions differ from the reference spectra for microcrystallites due to electrostatic orientation of amino acid zwitterions by the metal nanoisland film. Moreover, non-additive peaks are observed in the spectrum of the mixture of amino acids adsorbed on SNF, which means that intermolecular interactions between adsorbed amino acids are very significant. The results indicate the need for a thorough analysis of the Raman spectra from amino acid solutions in the presence of a nanostructured metal surface, and may also be of interest for studying molecular properties and intermolecular interactions.

In this work, a ZIF-67/MWCNTs/Nafion sensor platform was constructed based on the good adsorption capacity of ZIF-67, the electrical conductivity of multiwalled carbon nanotubes (MWCNTs) and the excellent chemical stability of Nafion for the detection of Cu2+ in water. Meanwhile, the modified materials were characterized by scanning electron microscopy (SEM), Transmission electron microscopy (TEM), BET specific surface area test, X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and Fourier transform infrared spectrometry (FT-IR). Cyclic voltammetry (CV), electrochemical impedance (EIS), and square wave solvation voltammetry (SWSV) electrochemical methods were used to perform applied test studies on ZIF-67/MWCNTs/Nafion/GCE. The results show that ZIF-67/MWCNTs/Nafion/GCE has high sensitivity (57.5 μA/μM) and a low limit of detection (15.0 nM) for the electrochemical detection of Cu2+ ions in an electrochemical sensing system. It has high adsorption selectivity for Cu2+, and the recovery of Cu2+ in real water reached 98.6%-103%. The modified electrode has good repeatability, reproducibility, anti-interference, and stability, which makes this sensing platform can be practically applied to the detection of domestic water.

Dendrite growth and parasitic reactions with liquid electrolyte are the two key factors that restrict the practical application of the lithium metal anode. Herein, a bis(benzene sulfonyl)imide based single-ion polymer artificial layer for lithium metal anode is successfully constructed, which is prepared via blending the as-prepared copolymer of lithiated 4, 4’-dicarboxyl bis(benzene sulfonyl)imide and 4,4’-diaminodiphenyl ether on the surface of lithium foil. This single-ion polymer artificial layer enables compact structure with unique continuous aggregated Li+ clusters, thus reducing the direct contact between lithium metal and electrolyte, and ensuring Li+ transport fast and homogeneous simultaneously. Based on which, the coulombic efficiency of the Li|Cu half-cell is effectively improved, and the cycle stability of the Li|Li symmetric cell can be prolonged from 160 h to 240 h. Surficial morphology and elemental valence analysis confirm that the bis(benzene sulfonyl)imide based single-ion polymer artificial layer effectively facilitates the Li+ uniform deposition and suppresses parasitic reactions between lithium metal anode and liquid electrolyte in the LFP|Li full-cell. This strategy provides a new perspective to achieve steady lithium metal anode, which can be a promising candidate in practical application.

With this article, impact of effluent mixed water with the quality of the Mansagar Lake has been established by evaluating the physico-chemical parameters and the heavy-metal contents experimentally. The process of calculating water quality and the metal pollution quality indices is also explained in brief with respect to selected sample locations and varied environmental conditions (Pre- and Post-Monsoon season). Distribution trends of Pearson‘s correlation factor have also been discussed to establish their relation among the physico-chemical parameters and the heavy-metal contents for varied environmental conditions. In the end, detailed discussion on observations made during this study and useful recommendations are also elaborated in details. With this article, we intend to present a document for better understanding of the water quality of this lake in view of futuristic management strategies to be adopted to maintain it heritage values.

The efficiency of cold sheet and strip rolling of steels and non-ferrous metals in the main depends on the quality of the technological lubricant and its cost. In this regard, it is important to develop new compositions of effective metal-working coolants (MWC) having low cost and providing the maximum reduction in the friction coefficient. We developed and tested the new compositions of the MWC on basis of chicken fat, and mono- and diglycerides and their esters of boric acid synthesized from the wastes of sunflower oil production. The MWC were tested in DSEA on laboratory rolling mill 100x100 with a roll diameter of 260 mm during steel 08Kp rolling. The efficiency of the coolants was determined by the factor of metal stretch forming λ and the coefficient of friction μ in the deformation zone which was found by forward slip method. We found the metal-working coolant with 100 % concentration of boric acid esters of mono- and diglycerides is the most effective in steel rolling. Thus the new MWC on basis of boric acid esters of mono- and diglycerides synthesized from the wastes of sunflower oil production can be recommended for use in rolling of structural steels on account of availability, high efficiency, and a low cost.

This study examined the effects of blending decanol, an oxygenated fuel, with diesel on diesel engine performance and emissions. Experiments were conducted on a single-cylinder engine at 1700 rpm and 2700 rpm, using diesel/decanol blends at 10%, 30%, and 50% by volume (D90de10, D70de30, D50de50). Results showed that brake thermal efficiency decreased with higher decanol ratios at low speeds. In contrast, brake specific fuel consumption and brake specific energy consumption increased due to decanol's lower calorific value. Regarding emissions, decanol blending reduced NOx, CO, HC, and smoke. NOx emissions were lowered by the cooling effect resulting from decanol's higher latent heat of vaporization and lower calorific value, especially at low speeds. CO and HC emissions declined as decanol's oxygen content promoted oxidation, reducing incomplete combustion. Smoke emissions were minimized in fuel-rich zones by preventing unburned carbon particle formation. This study highlights decanol's potential as an eco-friendly diesel blending option. Future work should optimize blending ratios and injection settings to enhance diesel engine performance.

This study evaluates the viability of n-octanol as an alternative fuel in a direct-injection diesel engine, aiming to enhance sustainability and efficiency. Experiments employed varying blends of n-octanol (10%, 30%, and 50% by volume) with pure diesel, analyzing impacts on engine performance and emissions. The methodology involved testing each blend in a single-cylinder engine, measuring engine performance parameters such as brake torque and brake power under full load conditions across an engine speed range from 1400 to 2500 rpm. Comparative assessments of performance and emission characteristics at a constant engine speed of 1700 rpm were also conducted with varying loads. Results indicated that while n-octanol blends consistently improved brake thermal efficiency, they also increased brake specific fuel consumption due to the lower energy content of n-octanol. Consequently, while all n-octanol blends reduced nitrogen oxides (NOx) emissions compared to pure diesel, they also significantly decreased carbon monoxide, hydrocarbons, and smoke opacity, presenting a comprehensive reduction in harmful emissions. However, the benefits came with nuanced trade-offs: notably, higher concentrations of n-octanol (especially the 50% blend) led to a relative increase in NOx emissions as the octanol ratio increased. The study concludes that n-octanol significantly improves engine efficiency and reduces diesel dependence, but optimizing the blend ratio is crucial to balance performance improvements with comprehensive emission reductions.

This article systematically reviews the research achievements on the MnOx/TiO2 catalyst doped with transition metals or rare earth metals for the catalytic selective catalytic reduction of NH3 (SCR-NH3) reaction. The Methodi Ordinatio systematic literature analysis method was employed to rank relevant articles based on journal impact factors, publication years, and citation counts. The ranking data shows that the undoped MnOx/TiO2 catalysts exhibit a catalytic efficiency of up to approximately 90% for NOx reduction, while the doped MnOx/TiO2 catalysts with transition metals or rare earth metals can achieve a maximum reduction efficiency of 100%. Among all the doped metals, the catalyst doped with nickel demonstrates the best NOx reduction performance. The comprehensive literature research concludes that MnOx/TiO2-based SCR catalysts, especially those doped with transition metals or rare earth metals, have significant catalytic efficiency and development potential in reducing NOx emissions in SCR reactions.

Responding to an urgent call for effective and cost-efficient enforcement of emission regulations from ocean-going vessels (OGVs) at sea, the Royal Belgian Institute of Natural Sciences, one of the 17 official partners of the Belgian coastguard structure, launched its airborne sniffer program in 2015. A custom-built sniffer sensor was installed on board of the Belgian coastguard aircraft and has been used for the in-situ measurement of SO2 and NOx in OGV exhausts, providing non-compliance alerts to port inspection authorities in Belgium and other EU member states. To guarantee the consistency in quality and reliability of the airborne non-compliance alerts, the standard operational procedures and measurement methodology have been described and recorded in a sniffer quality management system (SQMS). As part of the SQMS, alerting thresholds for non-compliance with SO2 and NOx standards were defined based on the emission limits and the measurement uncertainty. In addition, compliant measurements for the fuel sulfur content (FSC) were shared through Thetis-EU, which is the sulfur inspection database hosted by the European Maritime Safety Agency (EMSA). By providing both non-compliance alerts and compliant measurements to port inspection authorities, the coastguard aircraft fulfills a first-step in the enforcement chain. This article demonstrates that the reported alerts have not only led to several sanctions, but the analysis also showed that the provision of airborne alerts improved the efficiency of the port inspection authorities drastically, resulting in a cost-efficient improvement of their enforcement strategy. Port inspection authorities were able to follow-up on 46% of the generated FSC alerts. In addition, 43% of the alerted OGVs, which were followed up, were confirmed as non-compliant after a port inspection. Accordingly, conditions were in place to effectively sanction 20% of the non-compliant observations. For NOx alerts, a limited follow-up was done by port inspection authorities and none of the alerts were confirmed by those inspections, which is mainly due to the lack of suitable inspection mechanisms and the absence of additional EU implementation regulations on NOx emission inspections. Aiming at paving the way for a stricter enforcement of airborne non-compliance alerts, a validation analysis was done between the airborne FSC measurements and reference FSC measurements. In addition to onboard measurements from exhaust gas cleaning systems (EGCS), analyzes of fuel samples were also carried out by port inspection authorities in order to acquire reference measurements. The validation analysis presented in this study showed that the empiric deviation of the airborne FSC measurements with the reference measurements was significantly lower than the uncertainty used in the reporting thresholds. It has also been shown that aerial measurements provide evidence-based data that, given an appropriate confidence interval, has the potential to be considered reliable legal evidence.

Understanding of the decisive role of the interaction mechanism and kinetics in the combustion processes is highly relevant for the elaboration of optimal conditions for obtaining Mo-Cu composite powders. From this perspective, the efficient delivery of the reduction mechanism of copper and molybdenum oxides with combined Mg + C reducing agents at high heating rates is crucial to develop a valuable approach for the combustion synthesis of Mo-Cu composite powders. Herein, we shed light on the mechanism of the reactions in all the studied binary, ternary and quaternary systems contemporaneously demonstrating the effect of the heating rate on the conversion degree. The combination of two highly exothermic and speedy reactions (MoO3+3Mg and CuO+Mg vs MoO3+CuO+4Mg) led to a slow interaction with weak self-heating (dysynergistic effect) due to a change in the reaction mechanism. On the other hand, it has been shown that during the simultaneous utilization of the Mg and C reducing agents, the process begins exclusively with carbothermic reduction, and at relatively high temperatures it continues with magnesiothermic one. The effective activation energy values of the magnesiothermic stages of the studied reactions were determined by Kissinger isoconversional method.

The effect of COVID-19 confinement regulations on air quality in the northwestern Alps is here assessed based on measurements at five valley sites in different environmental contexts. Surface concentrations of nitrogen oxides, ozone, particle matter, together with size, chemical, and optical (light absorption) aerosol properties, complemented by observations along the vertical column are considered. The 2020 concentration anomalies relative to previous years’ average are compared with the output of a machine learning algorithm accounting for weather effects and a chemical transport model, their difference being within 10–20 %. Even in the relatively pristine environment of the Alps, the «lockdown effect» is well discernible, both in the early confinement phase and in late 2020, especially in NOx concentrations (NO decreasing by >80 % and NO2 by >50 %). While ozone shows little variation, secondary aerosols increase due to enhanced transport from the neighbouring Po basin and coarse particles decrease due to missing resuspension by traffic and, in the city, to the shutdown of a steel mill. The NO2 vertical column density decreases by >20 %, whereas the aerosol profile is mainly influenced by large-scale dynamics, except a shallow layer about 500 m thick possibly sensitive to curtailed surface emissions.

In this research we are reporting gas sensing properties of TiO_2-x/TiO₂-based hetero-structure, which was ‘self-heated’ by current that at constant potential passed through the structure. Amperometric measurements were applied for the evaluation of sensor response towards ethanol, methanol, n-propanol and acetone gases/vapors. The sensitivity towards these gases was based on electrical resistance changes, which were determined by amperometric measurements of current at fixed voltage applied between Pt-based contacts/electrodes deposited on TiO_2-x/TiO₂-based layer. XRD analysis revealed the formation of TiO_2-x/TiO₂-based hetero-structure, which is mainly based on Ti₃O₅/TiO₂ formed during hydro-thermal oxidation based sensing layer preparation process. Additionally, photoluminescence and time-resolved photoluminescence decay kinetics based signals of this sensing structure revealed the presence of TiO₂ mainly in the anatase phase in the TiO_2-x/TiO₂-based hetero-structure, which was formed at 400°C annealing temperature. The evaluation of TiO_2-x/TiO₂-based gas sensing layer was performed at several different temperatures (25°C, 72°C, 150°C, 180°C) and at these temperatures different sensitivity to aforementioned gaseous materials was determined.

Metal additive manufacturing (AM), commonly referred to as 3D printing with metals, is an innovative technology with significant potential to transform industries such as aerospace, automotive, and healthcare. Despite its promise, the field faces several challenges that impact both its technical feasibility and economic viability. This paper explores the primary technical challenges, including material properties and processing complexities, such as the need for precise control of thermal gradients and the mitigation of defects like porosity and residual stresses. Additionally, it addresses the economic barriers, including high initial equipment costs, the need for specialized knowledge, and the relatively slow build speeds compared to traditional manufacturing methods. By examining these challenges, this paper aims to provide a comprehensive overview of the current state of metal additive manufacturing and suggest potential pathways for overcoming these obstacles to facilitate wider adoption and technological advancement in the field.

Toxic metal wastewater is a challenge for exposed terrestrial, aquatic environments and the recyclability of the water, prompting inputs for the development of promising treatment methods. Consequently, the rGO/ZnONP nanocomposite was synthesized at room temperature for four hours and was tested for adsorption of cadmium and lead in wastewater. The optimized nanocomposite had the lowest band gap energy (2.69 eV) and functional group interactions were at 516, 1220, 1732, 3009, and 3460 cm-1. The nanocomposite showed saturation of ZnO nanoparticles on rGO with a weight percentage of zinc (60.02 %), oxygen (22.96 %), and carbon (16.58 %), and the micrograph showed slight agglomeration on the sheet surface. The nanocomposite’s D and G band intensities were almost the same constituting the ZnO presence on rGO from the raman spectrum. The adsorption equilibrium time for cadmium and lead was reached within 10 and 90 minutes with efficiencies of ~ 100 %. Sips and Freundlich were best fitting the cadmium and lead adsorption data (R2 ~ 1), therefore the adsorption was a multilayer coverage for lead and a mixture of heterogenous and homogenous coverage for cadmium adsorption. Both adsorptions were best fitted by the pseudo first order model, suggesting the multilayer coverage dominance. The adsorbent was reused for three and seven times for cadmium and lead. The nanocomposite showed selectivity towards lead (95 %) and cadmium (100 %) in the interfering wastewater matrix. Conclusively, the nanocomposite may be embedded within upcoming lab-scale treatment plants which could lead to further upscaling and serving as industrial wastewater treatment material.

Wastewater contaminated with antibiotics is a major environmental challenge. We developed here the green synthesis of bio-graphenes by using natural precursors (Xanthan, Chitosan, Boswellia, Tragacanth). The use of these precursors can act as templates to create 3D doped graphene structures with special morphology. Also, this method is a simple method for in-situ synthesis of doped graphenes. The elements present in the natural polymers (N) and other elements in the natural composition (P, S) are easily placed in the graphene structure and improve the catalytic activity due to the structural defects, surface charges, increased electron transfers, and the high absorption. In this mechanism, O2 dissolved in water absorbs onto the positive charged C in doped graphenes to create oxygenated radicals, which enables the degradation of antibiotic molecules. Light irradiation increases the amounts of radicals and rate of antibiotic removal. The results have shown that the hollow cubic Chitosan-derived graphene has shown the best performance due to the doping of N, S, and P. The Boswellia-derived grapheme shows the highest surface area, but lower catalytic performance, which indicates the more effective role of doping in the catalytic activity. The effect of oxygen and light were also studied to accelerate the degradation process.

: AlF3 has interesting electrophysical properties, due to which the material is promising for applications in supercapacitors, UV coatings with low refractive index, excimer laser mirrors, and photolithography. The formation of AlF3-based nano- and micro-wires can bring new functionalities to AlF3 material. AlF3 nanowires be used, for example, in functionally modified microprobes for scanning probe microscopy. In this work, we investigate the AlF3 samples obtained by the reaction of initial aluminum with aqueous hydrofluoric acid solution of different concentrations. All the samples were obtained under normal conditions. The morphology of the nanowire samples is studied by scanning electron microscopy. Quantitative energy-dispersive x-ray spectroscopy (EDS) spectra are obtained and analyzed with respect to the feedstock and each other.

: AlF3 has interesting electrophysical parameters, due to which the material is promising for applications in supercapacitors, UV coatings with low refractive index, excimer laser mirrors, and photolithography. The formation of AlF3-based nano- and micro-wires can bring new functionalities to AlF3 material. AlF3 nanowires be used, for example, in functionally modified microprobes for scanning probe microscopy. In this work, we investigate the AlF3 samples obtained by the reaction of initial aluminum with aqueous hydrofluoric acid solution of different concentrations. All the samples were obtained under normal conditions. The morphology of the nanowire samples is studied by scanning electron microscopy. Quantitative energy-dispersive x-ray spectroscopy (EDS) spectra are obtained and analyzed with respect to the feedstock and each other.

Antioxidants are molecules that neutralize free radicals. In general, the reaction mechanisms of antioxidants are well known. The main reaction mechanisms of antioxidants are electron transfer (ET), proton transfer (PT), H atom transfer (HAT) and radical adduction (RAF). The study of these mechanisms is helpful to understand how antioxidants control high free radical levels on the cell. There are many studies focused on determine the main mechanism of an antioxidant to neutralize a wide spectrum of radicals, mainly reactive oxygen species (ROS) type radicals. Most of these antioxidants are polyphenols type compounds. Some esters, amides and metal-antioxidants have shown antioxidant activity. There are few experimental and theoretical studies about the antioxidant reaction mechanism of the aforementioned compounds. In this work, we shown the reaction mechanism proposed of an amide and its metal-antioxidant counterpart. We show how the presence of the metal increase the electron transfer on polar media and the H transfer in non-polar media. Even though, esters and amides are non-polar compound, the scavenger activity is good for the metal-antioxidant compound in no-polar media

Using agronomic measures to remediate heavy metals on farmland is the main measure to achieve the safe utilization of crops. Investigating the effects of applying different fertilizers on the uptake, and translocation of Chromium (Cr) in maize and on the effectiveness of Cr in soil under Cr contamination of farmland is of great theoretical and practical significance to achieve the safe utilization of arable land and safe production of agricultural products. Under field trial conditions, different fertilizer types were set up, including ammonium sulfite, calcium-magnesium phosphate, and diammonium phosphate. locally formulated fertilizers (urea-ammonium phosphate-potassium chloride) serving as the control, with Biochar and conditioner PX5B were chosen to compare the impacts of each. To study the effects of different fertilizer types on maize yield, Cr content in the plant, bioconcentration factor, translocation factor and available content of Cr in the soil. The results showed that Compared with the formulated fertilizer, all treatments could improve pH, soil organic matter (SOM） and reduce the effective state of Cr content in the soil by 15.05% to 42.66%. While the Cr content of maize grains treated with biochar and conditioner PX5B was 0.80 mg·kg-1 and 0.88 mg·kg-1 with reduction rates of 39.95% and 33.83%, respectively. The Cr content of maize grains treated with various fertilizer treatments ranged from 0.82 to 1.32 mg·kg-1 with reduction rates of 0.75% to 38.19%. The Cr content of maize grains could be brought down to below the national food safety standards of China(1.0 mg·kg-1) using urea – calcium magnesium phosphate - potassium chloride, urea - diammonium phosphate - potassium chloride, ammonium sulfite – calcium magnesium phosphate - potassium chloride and ammonium sulfite, urea – calcium magnesium phosphate - potassium chloride and the two conditioner treatments. Among the different fertilizer treatments, the best fertilizer treatment for reducing the effective state Cr content of soil and the Cr content of maize grains was ammonium sulfite-calcium-magnesium-phosphate fertilizer-potassium chloride, which could achieve similar reductions as the two conditioners, while it also had a certain reduction effect on the Cr content in maize roots and straws and on the aboveground bioconcentration factor（BCF） and the root-to-straw translocation factor（PTF） of maize for Cr. Therefore, the combination of ammonium sulfite and calcium magnesium phosphate is the best fertilizer combination to block the absorption of Cr by maize and has some implications for the fertilization of farmland under acidic soil conditions of Cr contamination.

Heavy metals toxicity is a grave environmental issue in contemporary times. Phytoremediation is economic, effective and ecofriendly approach to decontaminate and remediate metal contaminated areas. Phenolic and Flavonoid content are important abiotic stress markers. The individual and combined impacts of toxiferous metals Arsenic (As), Cadmium (Cd) and (Copper) Cu were employed in recent studies to investigate their effect on Total flavonoids content (TFC) and total phenolic content (TPC) in various parts of Hydrocotyle umbellata L. to explore the role of plant in abating metal contamination. Folin- ciocalteu and AlCl 3 methods were used for investigating TPC and TFC respectively. Two-way ANOVA and CART model were employed for statistical analysis. Highest TPC was examined in decreasing order as leaf & gt; stem & gt; root in case of all the metals. Whereas highest TFC was found in all plant parts when subjected to As toxicity, and the lowest TFC was found in stem of the plant in respect to Cu toxicity. There was significant effect on TPC on plant part when subjected to Cu and As stress, but so significance was observed in plant part in case of Cd and combined metal stress. Treatment concentration had no significant effect on TPC when subjected to unique impact of all the three metals but had significant effect in case of combined metal stress. Similarly, in case of TFC no significant effect was recorded in case of plant part in all the stress types. But treatment amount has significant impact on Cd and combined metal stress. Metal type has significant effect on TPC and TFC. Whereas plant part has significant impact on TPC but non-significant values were observed on TFC in this case. This study epitomizes TPC and TFC in plants as effective and viable tool to pertain their role in phytoremediation against metal contamination. Therefore H. umbellata L. can be exerted for successful assemblage and decontamination of Cd, Cu and As in different plant parts.

Sequential reactions of aminoalkynes represent a powerful tool to easily assembly biologically important polyfunctionalized nitrogen heterocyclic scaffolds. Metal catalysis often plays a key role in terms of selectivity, efficiency, atom economy and green chemistry of these sequential approaches. This review examines the existing literature on the applications of reactions of aminoalkynes with carbonyls which are emerging for their synthetic potential. Aspect concerning the features of the starting reagents, the catalytic systems, alternative reaction conditions and the pathways as well as the possible intermediates are provided.

Abstract: Heavy metals (HMs) contamination is one of the main among abiotic factors affecting crop productivity and also threatens human health via consuming metal contaminated crops as a food source. Over the past few years, HMs have drawn a lot of attention due to their increased use for commercial purposes and their harmful effects on plants and other life forms, thus threatening human survival. However, in recent years, several methods have been adopted to combat the harsh effects of HMs. After phytohormones, use of mineral nutrients such as selenium (Se) in the prevention of HM stress has been explored by the researchers more recently. Selenium is an important micronutrient widely known for its antioxidant properties in both plants and animals. Exogenous Se inhibits metal uptake and its translocation and also improves the antioxidant system, thus imparts resistance to HM toxicity in plants. Moreover, Se also regulates the production of various osmolytes in cells that helps in developing cell osmolarity. Selenium also induces the production of different types of secondary metabolites (SMs) that are also involved in plant's secondary defense mechanisms to different stresses. Uptake of mineral nutrients is a vital process for plant growth and development, which is also positively correlated with Se under metalloid toxicity. However, in order to understand the exact mechanism of Se in HM tolerance, different metabolic processes stimulated by Se and their pathways need to be explored. Hence, this review focuses on the role of Se on nutritional status, antioxidants metabolism, interaction with phytohormones and its role in the regulation of various genes involved in Se induced HM tolerance. Thus, this study will help researchers in the future for the improvement of HM tolerance via Se application in plants.

Co-based catalysts have gained significant attention in recent years due to their excellent ability to activate C-H bonds and high selectivity towards olefins, despite being a non-noble and environmentally unfriendly metal. However, further improvements are necessary for practical utilization, particularly in terms of activity and anti-carbon deposition capacity. In this study, we synthesized Al₂O₃ nanorods with abundant pentacoordinated Al³⁺ (Al³⁺_penta) sites. The supported Co on the Al₂O₃ nanorod (Co/Al₂O₃-NR) exhibited higher selectivity (>96% propylene selectivity) and stability (deactivation rate 0.15 h^-1), compared to Co supported on an Al₂O₃ nanosheet with fewer pentacoordinated Al³⁺ sites. Various characterizations confirmed that Co(II) mainly exists as CoAl₂O₄ rather than Co₃O₄ in the form of Co/Al₂O₃-NR, which inhibits the reduction of Co(II) to Co0 and improves catalyst stability accordingly.

Metal halide perovskites (MHPs), in particular lead-based halide perovskites have earned a recognized fame in several fields for their outstanding optoelectronics properties including direct generation of free charge carriers, optimal ambipolar charge carrier transport properties, high absorption coefficient, point-defect tolerance, and compositional versatility. Nowadays, this class of materials represents a real and promising alternative of silica for the photovoltaic technologies. This worthy success led to a growing interest in the exploration of MHP materials in other hot research fields such as the solar-driven photocatalytic water splitting towards hydrogen production, CO2 reduction to CO and CH4, useful organic reactions such as organic synthesis (formation of C-C, C-N, and C-O bonds), and pollutants and dye degradation. Nevertheless, many of these perovskite materials showed air and moisture instability problems that considerably hinder their practical application for photocatalytic water splitting and photodegradation of CO2. Moreover, if the chemical instability is a problem that can be in part mitigated by the optimization of the lattice structure, the presence of lead represents a real problem for the practical application of these type of materials in commercial devices. To successfully overcome this problem, lead-free metal halide perovskites (LFMHPs) have gained increasing interest thanks to their promising optoelectronic properties, comparable to lead-based materials, and their eco-friendly nature. Among all the lead-free perovskite alternatives, this mini review will focus the attention on the bismuth-based perovskites and perovskite derivatives with specific focus on solar-driven photocatalysis application for H2 evolution.

Heavy metals contamination in groundwater often occurs in various industrial processes. Stud-ies have confirmed that polysulfide could reduce hexavalent chromium to trivalent chromium, achieving the effect of in-situ stabilization. For other heavy metals contamination in groundwa-ter, whether polysulfide also had a stabilizing ability to achieve in-situ remediation. This re-search focused on heavy metals except for chromium that often contaminated in groundwater, including lead, nickel, zinc, copper, and cadmium to explore the feasibility of using calcium polysulfide (CaSx) as an in-situ stabilization technology for these heavy metals contamination groundwater. Results showed that CaSx had a great removal efficiency for heavy metals lead, nickel, zinc, copper, and cadmium. However, for nickel, zinc, copper and cadmium, when CaSx was added excessively, complexes would be formed, causing the result of re-dissolve and this would also reduce the removal efficiency. Since it is difficult to accurately control the dosage of agents for in-situ groundwater remediation, the concentration of re-dissolved nickel, zinc, cop-per, and cadmium may not be able to meet the groundwater control standards. CaSx had high lead removal efficiency, and it would not cause re-dissolution due to excessive CaSx dosing. CaSx can be used as an in-situ stabilization technique for lead contaminated groundwater.

The purpose of this study was to arrange a green roof on a sheet metal house to achieve winter heat preservation and summer thermal insulation using different plants and soil media, and to maintain the advantage of cost-saving and quick installation of sheet metal houses. In terms of the research method, the roof insulation, heat preservation and plant growth index were tested. Plants were grown in 10 container-type green roofs on the sheet metal house roof, and the physical environment of the building was monitored for one year. Five containers of commercially-available culture soil and five containers of sustainable composite were used as the media for growing five kinds of plants, respectively. The control group only had a sheet metal house roof. There were 11 experimental modules for testing whether the green roofs had thermal insulation, heat preservation and plant growth effects on a general sheet metal house. The results showed that, regarding the thermal insulation benefit assessment, the Sedum acre cv. robustum of green roof Groups B to D caused the temperature to be 38.29°C lower than the surface of the simple sheet metal house roof in August, showing a temperature difference of 54%.

This review analyzes the preparation and characterization of metal organic frameworks (MOFs) and their application as photocatalysts for water purification. The study begins by highlighting the problem of water scarcity and the different solutions for purification, including photocatalysis with semiconductors such as MOFs. It also describes the different methodologies that can be used for the synthesis of MOFs, paying attention to the purification and activation steps. The characterization of MOFs and the different approaches that can be followed to learn on the photocatalytic processes are also detailed. Finally, the work reviews literature focused on the degradation of contaminants from water using MOF-based photocatalysts under light irradiation.

The Anderson insulating states in Au nanoparticle assembly are identified and studied under the application of magnetic fields and gate voltages. When the inter-nanoparticle tunneling resistance is smaller than the quantum resistance, the system showing zero Mott gap can be insulating at very low temperature. In contrast to Mott insulators, Anderson insulators exhibit great negative magnetoresistance, inferring charge de-localization in a strong magnetic field. When probed by the electrodes spaced by ~200 nm, they also exhibit interesting gate-modulated current similar to the multi-dot single electron transistors. These results reveal the formation of charge puddles due to interplay of disorder and quantum interference at low temperatures.

Intermetallic compounds are increasingly being expected to utilize in tribological environments, but to date the works are hindered by insufficient ductility at low and medium temperature. This paper presents a novel multiphase intermetallic alloy with the chemical composition of Mo-40Ni-13Si (at.%). Microstructure characterization reveals that a certain amount of ductile Mo phases formed during the solidification process of ternary Mo-Ni-Si alloy melt, which is undoubtedly beneficial to the ductility improvement of intermetallic alloy. Tribological properties of the designed alloy, including wear resistance, friction coefficient and metallic tribological compatibility, were evaluated under dry sliding wear test conditions at room temperature. Results suggested that the multiphase alloy possesses an excellent property for room-temperature wear applications, which is attributed to the unique microstructural features and thereby good combination in hardness and ductility. The corresponding wear mechanism is also reported by observing the worn surface, subsurface and wear debris of alloy, which to be found is soft abrasive wear.

Filamentous manganese (Mn) oxide particles, which occur in the suboxic zone of stratified waterbodies, are important drivers of diverse elemental cycles. Although these particles are considered to be bacteriogenic, the environmental factor responsible for their formation has not been identified. Based on this study of laboratory cultures of a model Mn(II)-oxidizing bacterium, the supply of algal extracellular polymeric substances (EPS) was shown to stimulate Mn(II) oxidation and thus the production of filamentous Mn oxide particles. This observation was consistent with results obtained for naturally occurring particles collected from a near-bottom layer (depth of ~90 m) in the northern basin of Lake Biwa, Japan, that is, most Mn particles resembling delta-MnO2 were associated with an EPS-like gelatinous matrix, which contained dead algal cells and was lectin-stainable. In the lake water column, EPS produced by photosynthesis sank to the bottom layer. The analysis of the quality of water samples, which have been collected from the study site for 18 years, reveals that the annual average total phytoplankton biovolume in the surface layer correlates with the density of filamentous Mn particles in the near-bottom layer. Among different phytoplankton species, green algae appeared to be the key species. The results of this study suggest that algal EPS production induces the formation of filamentous Mn oxide particles in the near-bottom layer of the northern basin of Lake Biwa.

The cement industry has significant environmental impacts, stemming from natural resources extraction and fossil fuels combustion. Notably, carbon dioxide (CO2) emissions are a major concern associated with cement production. The cement industry emits 0.6 tons of CO2 per ton of cement production, which is around 8 % of the total CO2 emissions in the world. Meeting the 13th United Nations Sustainable Goals, cement plants aim to achieve carbon neutrality by 2050, resulting from reduction in CO2 emissions (change in the composition of cementitious materials) and the adoption of carbon capture and utilisation (CCU) technologies. A promising approach involves converting CO₂ into valuable chemicals and fuels, such as methanol (MeOH) through the power-to-liquid (PtL) technologies. In this process, CO2 captured from cement industry flue gas with hydrogen generated from renewable sources through electrolysis of water, catalytically transformed into renewable methanol (e-MeOH), offering a sustainable solution. To achieve this, it is crucial to advance the development of novel, highly efficient catalysts specifically designed for direct CO2 hydrogenation. In this sense, this review discusses recent developments and improvements in CO2 catalytic conversion, emphasizing catalyst performance, selectivity, and stability.

This study presents the development of zirconium polycarboxylate gel systems as substrates for advanced fluorescence sensing devices. Zirconium-based metal-organic gels (MOGs) offer a promising alternative due to the robustness of the Zr-O bond, which provides enhanced chemical stability. In this work, zirconium polycarboxylate gels were synthesized using green solvents in a rapid room temperature method. Fluorescein, naphthalene-2,6-dicarboxylic acid and 4,4',4'',4'''-(porphine-5,10,15,20-tetrayl)tetrakisbenzoic acid were incorporated as fluorophores to give the gel luminescent properties, enabling it to be used as a sensor. These fluorophores produce specific changes in the perceived colour and intensity of the fluorescence emission upon interaction with different analytes in solution, allowing a qualitative identification of different solvents and compounds. However, the fragile structure of neat gels hinders reproducible quantitative analysis of fluorescence emission, so to increase mechanical stability during manipulation, a composite material was developed by combining the MOGs with quartz microcrystals, which proved to be a more reliable fluorescent system. The results show that the material can identify univocally different solvents and analytes in aqueous solutions by the quantitative analysis of the emissions intensities. This work presents an innovative approach to create advanced fluorescence sensors with improved mechanical properties and stability using zirconium polycarboxylate gels and multiple fluorophores.

Anthropogenic activity like Industrialization has unleashed vast quantities of organic pollutants, including heavy metals. The hazardous heavy metals can cause cancer, neurocognitive defects and wide-ranging health problems. The pollutants resist environmental degradation and can often accumulate in the environment. Microbial degradation of pollutants is a potentially efficient solution for pollution remediation. Amongst the heavy metals, lead contamination resulting from anthropogenic activity have resulted in tragic consequences since the advent of human civilization, even in 21^st century as demonstrated by the Flint water crisis in the US. Bioremediation of lead from the environment could be attempted by various strategies, including mitigation of human activity that causes it in the first place. Microbiome, specifically bacteria, mediated bioremediation can serve as a potent platform for remediating environmental pollution with heavy metals such as lead. Herein we will review the mechanisms and methods of microbial bioremediation of environmental heavy metals with a focus on lead and highlight the challenges and opportunities.