Prerpints.org logo
Preprint
Article

Zinc Oxide Loaded Cellulose-based Carbon Gas Sensor for Selective Detection of Ammonia

Altmetrics

Downloads

66

Views

41

Comments

0

A peer-reviewed article of this preprint also exists.

supplementary.docx (569.74KB )

Submitted:

13 November 2023

Posted:

14 November 2023

You are already at the latest version

Alerts
Abstract
Cellulose-based carbon (CBC) has been widely concerned with its porous structure, high specific surface area, and is liable to adsorb gas molecules and macromolecular pollutants. However, the application of CBC in gas sensing has been little studied. In this paper, ZnO/CBC heterojunction was formed by means of simple co-precipitation and high temperature carbonization. As a new ammonia sensor, the prepared ZnO/CBC sensor can detect ammonia compared with that of the previous pure ZnO ammonia sensor can not at room temperature. It has great gas sensing response, stability and selectivity to ammonia concentration at 200 ppm. This study provides a new idea for the design and synthesis of biomass carbon-metal oxide composites.
Keywords: 
Subject: Chemistry and Materials Science  -   Materials Science and Technology

1. Introduction

Ammonia is a colorless, toxic, corrosive substance with a strong odor and a choking effect. Excess ammonia can pose a huge threat to human health and to cause environment pollution. Different from other toxic gases, ammonia has a low boiling point of -33.5 ℃, a low melting point of -77.75 ℃, a low density of 0.771 g·L-1, a refractive index of 1.33, and a dipole moment of 1.42 d. These characteristics make ammonia an excellent gas sensor, and its sensors can be used in a variety of applications such as environmental monitoring, agriculture or medical diagnostics, and industrial waste dealing [1,2].
Zinc oxide is a metal oxide semiconductor material with wide band gap (3.37 eV), high bonding strength and large exciton binding energy (60 meV) at room temperature. Based on these properties, it is often used in gas sensors, chemical sensors, biosensors, cosmetics, energy storage, optical and electronic devices and other products [3,4,5,6,7]. The existing zinc oxide gas sensors show great gas sensing performance for carbon dioxide, ammonia and ethanol. The resistive gas sensor based on ZnO nanosheets was prepared by Srinivasulu et al. which has a large surface area and can quickly and highly detect carbon dioxide in the air [8]. The ZnO nanoflowers were prepared by Yu et al. which have great gas sensing properties for low concentrations of ammonia [9]. However, the original zinc oxide still has some shortcomings such as poor gas sensitivity, slow response and recovery time and poor selectivity. Therefore, many researchers have used by doping other elements or mixing zinc oxide with other metal oxides to prepare composite materials in order to improving gas sensing performance [10,11,12,13,14].
It is an effective way to improve the gas sensing performance of the sensor by introducing carbon material into the gas sensing material based on zinc oxide. Using activated carbon fiber as a template, Chao et al. synthesized ZnO/C nanoporous fibers by hydrothermal method. The materials showed great gas sensing performance to low concentrations of ethanol and acetone at optimum operating temperature [15]. The heterojunction ZnO/hollow porous carbon microtubule (CMT) prepared by Sun et al. from simple carbonized buttonwood fluff fibers showed a great gas sensing response to trace ammonia molecules [16]. Hu et al. prepared composite materials by generating zinc oxide particles on nitrogen-doped carbon sheets, and the heterogeneous structure improved the gas sensing ability of composite materials to ppb grade NO2 [17]. Cellulose, as a natural polymer material abundant on the earth, has a large number of hydroxyl functional group, excellent biodegradability and stable physical and chemical properties [18]. And compared with other carbon sources, cellulose is more available in nature, which can reduce the cost of producing carbon materials significantly. In recent years, there have been many reports on the application of cellulose-based carbon (CBC) as carbon materials in the field of supercapacitors and photocatalytic degradation by taking advantage of its excellent properties such as porous structure, huge specific surface area, and ability to adsorb gas molecules and macromolecular pollutants [19,20,21,22,23]. However, there are few researches on carbonizing cellulose into biomass carbon materials into ZnO-based gas sensors.
In this work, zinc oxide was prepared by a simple chemical precipitation method, and then it was carbonized with microcrystalline cellulose at high temperature, and ZnO/CBC were prepared for ammonia detection. Compared with the original ZnO-based ammonia sensor, due to the construction of the heterogeneous structure between ZnO and CBC, the composite has a great gas sensing response to a certain concentration of ammonia at room temperature, and has a better ammonia selectivity. The use of cellulose as the precursor of biomass carbon materials and combined with metal oxides to form composite materials provides a new reference in the field of gas detection.

2. Materials and Methods

2.1. Materials

Zinc acetate dihydrate (Zn(CH3COO)2·2H2O, 98%) was get from Anneji (Shanghai) Pharmaceutical Chemical Co., Ltd. Ammonia liquor (NH3·H2O, 26%-28%) was purchased from Sinopharm Chemical Reagent Co., Ltd. Microcrystalline cellulose (50 μm) was obtained from Aladdin Reagent (Shanghai) Co., Ltd. Deionized water was prepared in the laboratory.

2.2. Synthesis of ZnO/CBC

ZnO was prepared by a simple chemical deposition method. Add 0.25 g zinc acetate dihydrate and 0.5 g microcrystalline cellulose to 30 mL deionized water, add ammonia water under magnetic stirring in an oil bath at 90 °C, make the molar ratio of Zn2+ to OH- 1:15. Continued magnetically stirring at 90 ℃ for 1h. After the reaction, the solution was washed and centrifuged for several times until the pH was neutral, and then dried in a vacuum drying oven at 60 °C to obtain a white powder. The white powder was placed in a tube furnace at 600 °C and calcined by N2 for 2 hours. The black powder obtained was recorded as ZnO/CBC-60% (the ratio of zinc acetate dihydrate to microcrystalline cellulose). According to the same experimental methods, ZnO/CBC-33%, ZnO/CBC-50%, ZnO/CBC-66%, ZnO/CBC-71% and CBC with different zinc oxide contents were prepared.

2.3. Characterization

The morphology and size of the samples were characterized by field emission scanning electron microscopy (SEM, ZEISS Sigma 300) and transmission electron microscopy (TEM, FEI Tecnai F30). The crystal structure of the sample was characterized by X-ray diffraction (XRD, Bruker D2 PHASER) of copper target radiation at ambient temperatures with 2θ values of 10 to 80 degrees and scanning rates of 5°/mins. The chemical composition and elements of the samples were characterized by X-ray photoelectron spectroscopy (XPS, Thermo Scientific K-Alpha). Raman spectra were recorded using a Raman spectrometer (Raman, Horiba LabRAM HR Evolution) with a laser wavelength of 532 nm. In situ DRIFT spectroscopy was performed using Bruker VERTEX 80v infrared spectrometer. ZnO/CBC-60% was exposed to ammonia and pure nitrogen at room temperature. The Mott-Schottky curves of the samples were measured with an electrochemical workstation (CHI660E model), 0.5 M sodium sulfate solution is configured, Ag/AgCl is the reference electrode, platinum plate is the counter electrode.

2.4. Fabrication of gas sensing device

In order to perform electrical and sensing performance, a certain amount of samples were taken on an agate mortar and a small amount of deionized water was added to grind the samples to a sticky state. The grinding liquid was evenly coated on the interdigital electrode of the ceramic substrate and dried in a drying oven at 100 ℃. Gas sensing measurements are carried out using the self-made device shown in Figure 1. The static liquid-gas distribution method is used to generate ammonia gas environments with different concentrations. The calculation formula is shown as follows [24,25]：
C = 22.4 × ∅ × ρ × p × V 1 M × V 2 × 1000
where C (ppm) stand for target gas concentration, Ø stand for required gas volume fraction, ρ (g mL−1) stand for density of the liquid, p stand for purity of the liquid, V1 (μL) stand for volume of liquid, V2 (L) stand for volume of the chamber, and M (g mol−1) stand for molecular weight of the liquid.
The change in resistance of the sensor was measured by a multimeter. The response of the sensor was defined as:
S = R g − R a R a × 100 %
where Ra is the resistance of the sensor in the air, and Rg is the resistance of the sensor after it passes into the target gas.

3. Results

3.1. Characterization of ZnO/CBC

The XRD patterns of ZnO/CBC and CBC with different ZnO precursor contents are shown in Figure 2. ZnO/CBC showed sharp diffraction peaks at 2θ = 31.8°, 34.4°, 36.3°, 47.5°, 56.6°, 62.9°, 66.4°, 67.9°, 69.1°, 72.6° and 77.0°, which were in accordance with (100), (002), (101), (102), (110), (103), (200), (112), (201), (004) and (202) crystal planes, respectively, The strongest peak occurred on the (101) crystal plane. All diffraction peaks correspond to the standard hexagonal wurtzite structure (JCPDS-99-0111) [26,27]. No diffraction peaks from other phases or impurities were observed. These results indicated that pure ZnO structures were formed through precipitation. Since the amorphous carbon was prepared and its crystallinity is low, wide peaks with low signal strength appeared near 22 ° and 42 ° [28,29,30]. The diffraction peaked strength is weaker than ZnO, while there could not be shown in the XRD pattern of ZnO/CBC.
Figure 3 shows the SEM images of ZnO/CBC and pure carbon with different ZnO precursor contents. It can be seen from Figure 3b–e that ZnO has been successfully loaded on CBC. ZnO exhibited a flower-like structure when the precursor content was small. With the ZnO precursor content increasing, ZnO gradually changed into a rod-like structure, at mean while the aspect ratio also becoming larger. This was due to the increase in ammonia solution, which promoted oxidation. Zinc preferentially grew on the C axis [31]. Figure 3a shows that the surface of CBC was relatively smooth after high temperature carbonization. However, after loading ZnO, the surface of CBC becomes rough. EDS was used to conduct elemental analysis of ZnO/CBC-60%. It can be seen from Figure S1 that C, O and Zn have been evenly distributed on ZnO/CBC-60%, and the atomic ratios of C, O and Zn were 77.50%, 11.84% and 10.66%, respectively. Since aluminum foil was used as the substrate, the Al signal appeared.
In order to further understood the structure of ZnO/CBC-60%, TEM characterization was performed. As shown in Figure 4a,b, it can be clearly found that there were different lattice fringes at the boundary of CBC and ZnO. The lattice fringes near 0.136 and 0.282 nm correspond to the (201) and (100) crystal faces of ZnO, respectively [11,32]. The lattice fringes near 0.202 and 0.350 nm correspond to the (101) and (002) crystal faces of graphite, respectively [33]. The lattice fringes of ZnO and CBC were interwoven, which also confirmed the construction of heterojunctions between ZnO and CBC.
As shown in the Raman spectrum in Figure 5a, it can be observed that peak D and peak G of typical carbon materials were located at 1340 cm-1 and 1584 cm-1, respectively, where peak D represents sp3 hybrid carbon of disordered or defective carbon, while peak G corresponds to sp2 hybrid carbon of graphite structure [34]. The relative strength ratio (ID/IG) of peak D and peak G indicates the degree of graphitization of the material. The ID/IG values of pure carbon and ZnO/CBC-60% were 0.90 and 0.79, respectively, which were much higher than the ID/IG values of typical graphite, indicating that the prepared carbon materials were not highly crystalline and disordered materials exist. This was consistent with the observation of XRD. Moreover, the addition of ZnO improved the degree of disorder and defects in the structure of carbon materials [35]. The peaks at 80 cm-1 and 427 cm-1 in ZnO/CBC-60% correspond to E 2 l o w and E 2 h i g h , respectively. E 2 l o w was affected by Zn2+ gap defect, and E 2 h i g h was affected by O2- vacancy [36]. The simultaneous appearance of characteristic peaks of ZnO and carbon materials confirmed the successful preparation of ZnO/CBC. At the same time, it can be observed from Figure 6b that the D-peaks and G-peaks of ZnO/CBC-60% had a certain wave number displacement relative to pure carbon materials. It can be concluded that the heterojunction constructed by ZnO and cellulose-based carbon induces charge transfer between them [17].
In order to verify the elemental composition and surface chemical information of ZnO/CBC-60%, the materials were characterized by XPS. Figure 6a shows that ZnO/CBC-60% were mainly composed of Zn, C and O elements. Figure 6b was the high-resolution spectrum of Zn2p. In the figure, the peaks of Zn2p1/2 and Zn2p3/2 were 1044.0 eV and 1021.1 eV respectively, and the binding energy distance before the two peaks was 22.9 eV, which proved the existence of divalent zinc ions[37]. Figure 6c shows the high resolution spectrum of O 1s. O 1s can be deconvolved into three peaks centered on 529.5 eV, 531.2 eV and 532.2 eV. The peak at 529.5 eV is attributed to the O2- ion in the Zn-O bond in the ZnO wurtzite structure, and the peak at 531.2 eV is attributed to the Zn-O-C bond and the adsorbed hydroxyl group or water. The peak at 532.2 eV is attributed to the carbonate (C-O /C=O) species [38]. As shown in Figure 6d, three peaks appeared at 283.6 eV, 285.7 eV and 288.3 eV respectively, which belonged to the Zn-C bond, Zn-O-C bond and C=O bond respectively, indicating that the performance of ZnO/CBC-60% was different from that of pure ZnO [39].
Mott Schottky curve was used to determine the semiconductor type of the material to better explain the sensing mechanism of the material. Figure S2 shows the Mott Schottky curves of CBC and ZnO/CBC-60% at different frequencies measured at room temperature. It can be seen from the figure that the slopes of all curves are negative, indicating that CBC was a p-type semiconductor, and the prepared ZnO/CBC-60% also exhibited p-type semiconductor properties.

3.2. Results of Sensing Tests

Firstly, the gas sensing response of ZnO/CBC with different contents of CBC and ZnO precursors to 200 ppm ammonia at room temperature of 60% relative humidity was tested. When the sensor was in an air environment, the resistance of the sensor was at a stable value (Ra). When exposed to ammonia, the resistance of the sensor increased and reached a maximum value (Rg). When the sensor is exposed to air again, the resistance of the sensor will gradually return to the initial value (Ra). The resistance of CBC and ZnO/CBC increased gradually in ammonia environment and decreased gradually in air, which showed p-type semiconductor behavior. After testing the sensor, Figure 7a shows that when the ZnO precursor content was 60%, the sensor's gas sensing response to 200 ppm ammonia was the highest, reaching 27%. Therefore, zinc acetate/cellulose (wt%) =150 wt% was selected as the optimal ratio for preparing the required sensing material. At the same time, the ZnO/CBC-60% sensor was placed in the environment of methanol, isopropyl alcohol, ethanol and formaldehyde at 200 ppm at room temperature to test the gas sensing performance of the sensor to these gases, in order to verify the selectivity of the sensor to ammonia. It can be seen from Figure 7b that the gas sensing response of the sensor to ammonia is dozens of times that of other gases, indicating that the prepared ZnO/CBC-60% sensor had good selectivity to ammonia. This may be attributed to the fact that the heterostructure constructed between ZnO and CBC provided more active sites for the selective adsorption of ammonia molecules.
In order to further test the gas sensing performance of ZnO/CBC-60% for ammonia. Sensor was put in ammonia environment with five concentrations of 25 ppm, 50 ppm, 100 ppm, 150 ppm and 200 ppm at room temperature for gas sensing test. The gas sensing response of the sensor to ammonia with a concentration of 25-200 ppm at room temperature is shown in figure 8a. As the ammonia concentration increased, the gas sensing response of the sensor increased, which was in line with the expected goals of the experiment. Stability is one of the key parameters of gas sensing. We tested the stability of ZnO/CBC-60% sensor by placing the sensor in 200 ppm ammonia environment for five rounds of gas sensing tests. As shown in figure 8b, after five sensing cycled, the gas sensing performance of ZnO/CBC-60% sensor had not weakened, indicating that the sensor had good repeatability.
Preprints 90379 g008
Figure 8. (a) Response of ZnO/CBC-60% to ammonia with concentration of 25-200 ppm, (b) Repeatability evaluation of ZnO/CBC-60% for 200 ppm ammonia at RT.
Figure 8. (a) Response of ZnO/CBC-60% to ammonia with concentration of 25-200 ppm, (b) Repeatability evaluation of ZnO/CBC-60% for 200 ppm ammonia at RT.
Preprints 90379 g008
Relative humidity is an important factor affecting the performance of gas sensor [40]. as shown in Figure 9a, with the increase of relative humidity, the gas sensitivity of ZnO/CBC-60% sensor to ammonia was correspondingly weakened, which may be due to the fact that H2O molecules in the test environment preempted the active sites, so that NH3 molecules could not fully react with the materials, resulting in the decrease of gas sensing response[18].
The ZnO/CBC-60% sensor was put in an ammonia concentration environment of 200 ppm for one week. As can be seen from Figure 9b, the gas sensing response of the sensor to ammonia had not changed greatly, which indicated that the sensor had good stability.

4. Discussion

In order to prove that the gas sensing response of ZnO/CBC-60% was the result of the reaction with NH3 molecules, the material was analyzed by in-situ DRIFT spectroscopy. As shown in Figure 10a, after introducing the mixed gas of NH3 and N2, it can be observed that adsorption peaks of coordinated NH3 species corresponding to Lewis sites appeared near 929, 964, 1619 and 3334 cm-1 [41,42,43], and these peaks gradually became stronger with the increase of adsorption time. Figure 10b shows that the peak value was obviously weakened after N2 purging. These phenomena show that the adsorption and desorption of ammonia occurred on the surface of ZnO/CBC-60%, which explained the gas sensing response of ZnO/CBC-60% to ammonia.
Figure 11 shows the interface energy band diagram of ZnO/CBC sensor in air and ammonia. It can be seen from Mott Schottky curve that CBC was a p-type semiconductor, while ZnO was a typical n-type semiconductor, The combination of the two created a p-n heterojunction. Due to the difference in concentration of electrons and holes in the two materials, the free electrons ZnO conduction band will diffuse to CBC, and the holes in CBC will diffuse to ZnO until the Fermi level reached a new equilibrium [44,45]. This process made the energy band bend, forming a narrow depletion layer, forming an electron accumulation layer on the CBC side and a hole accumulation layer on the ZnO side. When ZnO/CBC sensor was exposed to ammonia, NH3 molecules will capture hole protons from CBC, and the hole accumulation layer will provide more adsorption sites for ammonia adsorption. In addition, NH3 molecules will release some electrons to ZnO/CBC, which will neutralize the holes and further widen the depletion layer on the CBC side, resulting in an obvious increase [46], in the resistance of the sensor, which was consistent with the phenomenon in gas sensing test.

5. Conclusions

In this experiment, ZnO was loaded on CBC, and the gas sensing response of ZnO/CBC loaded with different ZnO contents to ammonia at room temperature was studied by various the content of ZnO precursors. The composites were characterized by SEM, TEM, XRD, Raman and XPS. The results showed that ZnO had been successfully loaded on CBC. Subsequently, the gas sensing performance showed that the ZnO/CBC with 60% ZnO precursor content had better gas sensing response to 200 ppm ammonia at room temperature, reaching 27%. In addition, through five consecutive rounds of gas sensing response tests in 200 ppm ammonia environment, it was found that ZnO/CBC-60% exhibited good stability. At the same time, by comparing the gas sensing performance of several VOC gases, it was found that the material for ammonia had well selectivity. In-situ DRIFT spectroscopy proved that the sensing material did react with ammonia, and the ZnO/CBC-60% could provide more active sites for ammonia molecules because of the construction of heterojunction between ZnO and CBC. Therefore, ZnO/CBC composites had improved sensing performance. This study provides a new idea for the design and synthesis of biomass carbon-metal oxide composites.

Supplementary Materials

The following supporting information can be downloaded at the website of this paper posted on Preprints.org, Figure S1: (a-e) SEM images of the ZnO/CBC-60% and corresponding mapping images of C, O and Zn, (f) the EDS analysis of the prepared ZnO/CBC-60%; Figure S2: Figure S2. Mott-Schottky curves of (a) CBC, (b) ZnO/CBC-60%.

Author Contributions

Conceptualization, H.X., X.-P.L. and Y.-X.W.; methodology, H.X. and Z.-X.G.; software, H.X. C. G.; validation, H.X. and Z.-X.G.; formal analysis, L.-Z.H.; investigation, H.X.; resources, H.X., X.-P.L and Y.-X.W.; data curation, H.X. and Z.-X.G.; writing—original draft preparation, X.H.; writing—review and editing, H.X., X.-J.Y., X.-P.L. and Y.-X.W.; visualization, H.X.; supervision, L.-Z.H.; project administration, H.X., Y.-X.W. and X.-P.L; funding acquisition, X.-P.L. All authors have read and agreed to the published version of the manuscript.

Funding

This research was funded by the Central Financial Funds for the Forestry Science and Technology Promotion Application Project in China (2023TS01), Zhejiang A & F University Scientific Research and Development Fund Project grant number (2020RC032), the “Pioneer” and “Leading Goose” R&D Program of Zhejiang (2022C02023).

Data Availability Statement

The data presented in this study are available on request from the corresponding author.

Conflicts of Interest

The authors declare no conflict of interest.

References

  1. Danasa, A.S.; Soesilo, T.E.B.; Martono, D. N.; Sodri, A.; Hadi, A.S.; Chandrasa, G.T. The ammonia release hazard and risk assessment: A case study of urea fertilizer industry in Indonesia. IOP conference series: Earth and environmental science, 2019; IOP Publishing: 2019; pp. 012087. [CrossRef]
  2. Aarya, S.; Kumar, Y.; Chahota, R. K. Recent Advances in Materials, Parameters, Performance and Technology in Ammonia Sensors: A Review. J. Inorg. Organomet. Polym Mater. 2020, 30, 269–290. [Google Scholar] [CrossRef]
  3. Si, X.; Wei, Y.; Wang, C.; Li, L.; Ding, Y. A sensitive electrochemical sensor for ofloxacin based on a graphene/zinc oxide composite film. Anal. Methods 2018, 10, 1961–1967. [Google Scholar] [CrossRef]
  4. Dai, H.; Feng, N.; Li, J.; Zhang, J.; Li, W. Chemiresistive humidity sensor based on chitosan/zinc oxide/single-walled carbon nanotube composite film. Sensor Acturt B-Chem 2019, 283, 786–792. [Google Scholar] [CrossRef]
  5. Young, S.J.; Liu, Y.H.; Shiblee, M. N. I.; Ahmed, K.; Lai, L.T.; Nagahara, L.; Thundat, T.; Yoshida, T.; Arya, S.; Furukawa, H. Flexible ultraviolet photodetectors based on one-dimensional gallium-doped zinc oxide nanostructures. ACS Appl. Electron. Mater 2020, 2, 3522–3529. [Google Scholar] [CrossRef]
  6. Yu, S.; Chen, C.; Zhang, H.; Zhang, J.; Liu, J. Design of high sensitivity graphite carbon nitride/zinc oxide humidity sensor for breath detection. Sensor Acturt B-Chem 2021, 332, 129536. [Google Scholar] [CrossRef]
  7. Chauhan, R.; Kumar, A.; Tripathi, R.; Kumar, A. Advancing of zinc oxide nanoparticles for cosmetic applications. In Handbook of consumer Nanoproducts, Springer: Singapore, 2022; pp. 1–16. [CrossRef]
  8. Kanaparthi, S.; Singh, S. G. Chemiresistive sensor based on zinc oxide nanoflakes for CO2 detection. ACS Appl. Nano Mater 2019, 2, 700–706. [Google Scholar] [CrossRef]
  9. Zhang, Y.; Liu, T.; Hao, J.; Lin, L.; Zeng, W.; Peng, X.; Wang, Z. Enhancement of NH3 sensing performance in flower-like ZnO nanostructures and their growth mechanism. Appl. Surf. Sci 2015, 357, 31–36. [Google Scholar] [CrossRef]
  10. Ganesh, R. S.; Durgadevi, E.; Navaneethan, M.; Patil, V.; Ponnusamy, S.; Muthamizhchelvan, C.; Kawasaki, S.; Patil, P.; Hayakawa, Y. Tuning the selectivity of NH3 gas sensing response using Cu-doped ZnO nanostructures. Sensor Actuat A: Phy 2018, 269, 331–341. [Google Scholar] [CrossRef]
  11. Poloju, M.; Jayababu, N.; Reddy, M. R. Improved gas sensing performance of Al doped ZnO/CuO nanocomposite based ammonia gas sensor. Mater Sci Eng B-Adv 2018, 227, 61–67. [Google Scholar] [CrossRef]
  12. Zhao, Z.; Yang, H.; Wei, Z.; Xue, Y.; Sun, Y.; Zhang, W.; Li, P.; Gong, W.; Zhuiykov, S.; Hu, J. NH3 sensor based on 3D hierarchical flower-shaped n-ZnO/p-NiO heterostructures yields outstanding sensing capabilities at ppb level. Sensors-Basel 2020, 20, 4754. [Google Scholar] [CrossRef]
  13. Abdulsattar, M. A.; Jabbar, R. H.; Abed, H. H.; Abduljalil, H. M. The sensitivity of pristine and Pt doped ZnO nanoclusters to NH3 gas: A transition state theory study. Optik 2021, 242, 167158. [Google Scholar] [CrossRef]
  14. Ramesh, A.; Gavaskar, D.; Nagaraju, P.; Duvvuri, S.; Vanjari, S. R. K.; Subrahmanyam, C. Mn-doped ZnO microspheres prepared by solution combustion synthesis for room temperature NH3 sensing. Appl. Surf. Sci.Adv 2022, 12, 100349. [Google Scholar] [CrossRef]
  15. Chao, J.; Chen, Y.; Xing, S.; Zhang, D.; Shen, W. Facile fabrication of ZnO/C nanoporous fibers and ZnO hollow spheres for high performance gas sensor. Sensor Acturt B-Chem 2019, 298, 126927. [Google Scholar] [CrossRef]
  16. Sun, Q.; Wu, Z.; Zhang, M.; Qin, Z.; Cao, S.; Zhong, F.; Li, S.; Duan, H. M.; Zhang, J. Improved Gas-Sensitive Properties by a Heterojunction of Hollow Porous Carbon Microtubes Derived from Sycamore Fibers. ACS Sustainable Chem. Eng 2021, 43, 9. [Google Scholar] [CrossRef]
  17. Hu, J.; Yin, C.; Cheng, M.; Wei, T.; Liu, Q.; Li, W.; Ling, Y.; Zhang, Y.; Liu, B. Facile synthesis of N-doped carbon sheets-ZnO hybrids for NO2 sensing at ppb level. J. Alloys Compd 2022, 892, 162243. [Google Scholar] [CrossRef]
  18. Tu, H.; Zhu, M.; Duan, B.; Zhang, L. Recent progress in high-strength and robust regenerated cellulose materials. Adv. Mater 2021, 33, 2000682. [Google Scholar] [CrossRef] [PubMed]
  19. Shao, H.; Wu, Y.-C.; Lin, Z.; Taberna, P.-L.; Simon, P. Nanoporous carbon for electrochemical capacitive energy storage. Chem. Soc. Rev 2020, 49, 3005–3039. [Google Scholar] [CrossRef] [PubMed]
  20. Gan, L.; Geng, A.; Song, C.; Xu, L.; Wang, L.; Fang, X.; Han, S.; Cui, J.; Mei, C. Simultaneous removal of rhodamine B and Cr (VI) from water using cellulose carbon nanofiber incorporated with bismuth oxybromide: The effect of cellulose pyrolysis temperature on photocatalytic performance. Environ. Res 2020, 185, 109414. [Google Scholar] [CrossRef] [PubMed]
  21. Dou, T.; Zang, L.; Zhang, Y.; Sun, Z.; Sun, L.; Wang, C. Hybrid g-C3N4 nanosheet/carbon paper membranes for the photocatalytic degradation of methylene blue. Mater. Lett 2019, 244, 151–154. [Google Scholar] [CrossRef]
  22. Habibi, S.; Jamshidi, M. Sol–gel synthesis of carbon-doped TiO2 nanoparticles based on microcrystalline cellulose for efficient photocatalytic degradation of methylene blue under visible light. Environ. Technol 2019, 41, 3233–3247. [Google Scholar] [CrossRef]
  23. Gan, L.; Geng, A.; Xu, L.; Chen, M.; Wang, L.; Liu, J.; Han, S.; Mei, C.; Zhong, Q. The fabrication of bio-renewable and recyclable cellulose based carbon microspheres incorporated by CoFe2O4 and the photocatalytic properties. J. Cleaner Prod 2018, 196, 594–603. [Google Scholar] [CrossRef]
  24. John, R. A. B.; Shruthi, J.; Reddy, M. R.; Kumar, A. R. Manganese doped nickel oxide as room temperature gas sensor for formaldehyde detection. Ceram. Int 2022, 48, 17654–17667. [Google Scholar] [CrossRef]
  25. Chen, Q.; Ma, S.; Xu, X.; Jiao, H.; Zhang, G.; Liu, L.; Wang, P.; Gengzang, D.; Yao, H. Optimization ethanol detection performance manifested by gas sensor based on In2O3/ZnS rough microspheres. Sensor Acturt B-Chem 2018, 264, 263–278. [Google Scholar] [CrossRef]
  26. Mohan, S.; Vellakkat, M.; Aravind, A.; Reka, U. Hydrothermal synthesis and characterization of Zinc Oxide nanoparticles of various shapes under different reaction conditions. Nano Express 2020, 1, 030028. [Google Scholar] [CrossRef]
  27. Bagheri, F.; Haratizadeh, H. UV-activated CO2 sensor based on ZnO nanoparticles at low temperatures. Mater. Sci. Semicond. Process 2022, 141, 106422. [Google Scholar] [CrossRef]
  28. Liu, Y.; Lu, Y. X.; Xu, Y. S.; Meng, Q. S.; Gao, J. C.; Sun, Y. G.; Hu, Y. S.; Chang, B. B.; Liu, C. T.; Cao, A. M. Pitch-derived soft carbon as stable anode material for potassium ion batteries. Adv. Mater 2020, 32, 2000505. [Google Scholar] [CrossRef]
  29. Li, K.; Liu, Q.; Cheng, H.; Hu, M.; Zhang, S. Classification and carbon structural transformation from anthracite to natural coaly graphite by XRD, Raman spectroscopy, and HRTEM. Spectrochim Acta A 2021, 249, 119286. [Google Scholar] [CrossRef] [PubMed]
  30. Dong, Y.; Zhu, X.; Pan, F.; Deng, B.; Liu, Z.; Zhang, X.; Huang, C.; Xiang, Z.; Lu, W. Mace-like carbon fiber/ZnO nanorod composite derived from Typha orientalis for lightweight and high-efficient electromagnetic wave absorber. Adv. Compos. Hybrid Mater 2021, 4, 1002–1014. [Google Scholar] [CrossRef]
  31. Xu, H.; Wang, H.; Zhang, Y.; He, W.; Zhu, M.; Wang, B.; Yan, H. , Hydrothermal synthesis of zinc oxide powders with controllable morphology. Ceram Int 2004, 30, 93–97. [Google Scholar] [CrossRef]
  32. Chang, X.; Li, K.; Qiao, X.; Xiong, Y.; Xia, F.; Xue, Q. ZIF-8 derived ZnO polyhedrons decorated with biomass derived nitrogen-doped porous carbon for enhanced acetone sensing. Sensor Actuat B: Chem 2021, 330, 129366. [Google Scholar] [CrossRef]
  33. Chen, J.; Lv, H.; Bai, X.; Liu, Z.; He, L.; Wang, J.; Zhang, Y.; Sun, B.; Kan, K.; Shi, K. Synthesis of hierarchically porous Co3O4/Biomass carbon composites derived from MOFs and their highly NO2 gas sensing performance. Microporous Mesoporous Mater 2021, 321, 111108. [Google Scholar] [CrossRef]
  34. Qin, Z.; Wu, Z.; Sun, Q.; Sun, J.; Zhang, M.; Shaymurat, T.; Lv, C.; Duan, H. , Biomimetic gas sensor derived from disposable bamboo chopsticks for highly sensitive and selective detection of NH3. Chem. Eng. J 2023, 462, 142203. [Google Scholar] [CrossRef]
  35. Nada, A. A.; Orimolade, B. O.; El-Maghrabi, H. H.; Koiki, B. A.; Rivallin, M.; Bekheet, M. F.; Viter, R.; Damberga, D.; Lesage, G.; Iatsunskyi, I. Photoelectrocatalysis of paracetamol on Pd–ZnO/N-doped carbon nanofibers electrode. Appl. Mater. Today 2021, 24, 101129. [Google Scholar] [CrossRef]
  36. e Silva, R. L. d. S.; Franco Jr, A. Raman spectroscopy study of structural disorder degree of ZnO ceramics. Mater. Sci. Semicond. Process 2020, 119, 105227. [Google Scholar] [CrossRef]
  37. Hussain, M. Z.; Pawar, G. S.; Huang, Z.; Tahir, A. A.; Fischer, R. A.; Zhu, Y.; Xia, Y. Porous ZnO/Carbon nanocomposites derived from metal organic frameworks for highly efficient photocatalytic applications: A correlational study. Carbon 2019, 146, 348–363. [Google Scholar] [CrossRef]
  38. Hu, C.; Hu, X.; Li, R.; Xing, Y. MOF derived ZnO/C nanocomposite with enhanced adsorption capacity and photocatalytic performance under sunlight. J. Hazard. Mater 2020, 385, 121599. [Google Scholar] [CrossRef]
  39. Zhang, H.; Pan, Q.; Cai, W.; Shi, X.; Yang, D.-P.; Lin, H.; Qiu, E. C-doped ZnO Nanocomposites Molecularly Imprinted Photoelectrochemical Sensor for Ultrasensitive and Selective Detection of Oxytetracycline in Milk. Food Chem 2023, 426, 136535. [Google Scholar] [CrossRef] [PubMed]
  40. Liu, C.; Duan, Z.; Zhang, B.; Zhao, Y.; Yuan, Z.; Zhang, Y.; Wu, Y.; Jiang, Y.; Tai, H. Local Gaussian process regression with small sample data for temperature and humidity compensation of polyaniline-cerium dioxide NH3 sensor. Sensor Actuat B: Chem 2023, 378, 133113. [Google Scholar] [CrossRef]
  41. Fu, Y.; Wang, T.; Wang, X.; Li, X.; Zhao, Y.; Li, F.; Zhao, G.; Xu, X. Investigation of pn sensing transition and related highly sensitive NH3 gas sensing behavior of SnPx/rGO composites. Chem. Eng. J 2023, 471, 144499. [Google Scholar] [CrossRef]
  42. Li, Q.; Hou, Y.; Wang, J.; Liu, Y.; Xiang, N.; Huang, Z. Superiority of raw biomass and potassium hydroxide in preparation of ultrahigh nitrogen doping of carbon for NH3-SCR reaction. ACS Sustainable Chem. Eng 2020, 8, 11308–11316. [Google Scholar] [CrossRef]
  43. Wang, J.; Yan, Z.; Liu, L.; Zhang, Y.; Zhang, Z.; Wang, X. Low-temperature SCR of NO with NH3 over activated semi-coke composite-supported rare earth oxides. Appl. Surf. Sci 2014, 309, 1–10. [Google Scholar] [CrossRef]
  44. Liu, J.; Zhu, B.; Zhang, L.; Fan, J.; Yu, J. 0D/2D CdS/ZnO composite with nn heterojunction for efficient detection of triethylamine. J. Colloid Interface Sci 2021, 600, 898–909. [Google Scholar] [CrossRef] [PubMed]
  45. Qin, S.; Tang, P.; Feng, Y.; Li, D. Novel ultrathin mesoporous ZnO-SnO2 nn heterojunction nanosheets with high sensitivity to ethanol. Sensor Actuat B: Chem 2020, 309, 127801. [Google Scholar] [CrossRef]
  46. Tian, X.; Cui, X.; Xiao, Y.; Chen, T.; Xiao, X.; Wang, Y. Pt/MoS2/Polyaniline Nanocomposite as a Highly Effective Room Temperature Flexible Gas Sensor for Ammonia Detection. ACS Appl. Mater. Interfaces 2023, 15, 9604–9617. [Google Scholar] [CrossRef]
Preprints 90379 g001
Figure 1. Schematic diagram of gas detection. (1) Syringe, (2) Reaction chamber, (3) Interdigital electrode, (4) Victor 8145C TRMS digit multimeter, (5) Display screen, (6) Mainframe computer.
Figure 1. Schematic diagram of gas detection. (1) Syringe, (2) Reaction chamber, (3) Interdigital electrode, (4) Victor 8145C TRMS digit multimeter, (5) Display screen, (6) Mainframe computer.
Preprints 90379 g001
Preprints 90379 g002
Figure 2. XRD patterns of ZnO/CBC with different ZnO contents and CBC.
Figure 2. XRD patterns of ZnO/CBC with different ZnO contents and CBC.
Preprints 90379 g002
Preprints 90379 g003
Figure 3. SEM image of (a)CBC, (b)ZnO/CBC-33%, (c)ZnO/CBC-50%, (d)ZnO/CBC-60%, (e)ZnO/CBC-66%, (f) ZnO/CBC-71%.
Figure 3. SEM image of (a)CBC, (b)ZnO/CBC-33%, (c)ZnO/CBC-50%, (d)ZnO/CBC-60%, (e)ZnO/CBC-66%, (f) ZnO/CBC-71%.
Preprints 90379 g003
Preprints 90379 g004
Figure 4. TEM images of ZnO/CBC-60%.
Figure 4. TEM images of ZnO/CBC-60%.
Preprints 90379 g004
Preprints 90379 g005
Figure 5. (a) Raman spectra of ZnO/CBC-60% and CBC, (b) Partial enlarged Raman spectra of ZnO/CBC-60% and CBC.
Figure 5. (a) Raman spectra of ZnO/CBC-60% and CBC, (b) Partial enlarged Raman spectra of ZnO/CBC-60% and CBC.
Preprints 90379 g005
Preprints 90379 g006
Figure 6. XPS patterns of ZnO/C-60% and CBC. (a) Full spectrum of sample, (b) Zn 2p XPS spectra of ZnO/CBC-60%, (c) C 1s XPS spectra of ZnO/CBC-60%, (d) O 1s XPS spectra of ZnO/CBC-60%.
Figure 6. XPS patterns of ZnO/C-60% and CBC. (a) Full spectrum of sample, (b) Zn 2p XPS spectra of ZnO/CBC-60%, (c) C 1s XPS spectra of ZnO/CBC-60%, (d) O 1s XPS spectra of ZnO/CBC-60%.
Preprints 90379 g006
Preprints 90379 g007
Figure 7. (a) Response of different amounts of zinc oxide and CBC to ammonia at 200 ppm concentration, (b) Selectivity of ZnO/CBC-60% for ammonia.
Figure 7. (a) Response of different amounts of zinc oxide and CBC to ammonia at 200 ppm concentration, (b) Selectivity of ZnO/CBC-60% for ammonia.
Preprints 90379 g007
Preprints 90379 g009
Figure 9. (a) The response curves of ZnO/CBC-60% towards 200 ppm ammonia at different RHs, (b) Stability test of ZnO/CBC-60% for 200 ppm ammonia within one week at RT.
Figure 9. (a) The response curves of ZnO/CBC-60% towards 200 ppm ammonia at different RHs, (b) Stability test of ZnO/CBC-60% for 200 ppm ammonia within one week at RT.
Preprints 90379 g009
Preprints 90379 g010
Figure 10. (a) In-situ DRIFT spectroscopy of ZnO/CBC-60% by passing NH3+N2 mixture gases at RT for 40 mins, (b) Purged by N2 at RT.
Figure 10. (a) In-situ DRIFT spectroscopy of ZnO/CBC-60% by passing NH3+N2 mixture gases at RT for 40 mins, (b) Purged by N2 at RT.
Preprints 90379 g010
Preprints 90379 g011
Figure 11. The energy band structure diagram of n-type ZnO/p-type CBC hetero-contact.
Figure 11. The energy band structure diagram of n-type ZnO/p-type CBC hetero-contact.
Preprints 90379 g011
Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions or products referred to in the content.
Copyright: This open access article is published under a Creative Commons CC BY 4.0 license, which permit the free download, distribution, and reuse, provided that the author and preprint are cited in any reuse.
Prerpints.org logo

Preprints.org is a free preprint server supported by MDPI in Basel, Switzerland.

facebook logotwitter logolinkedin logo
MDPI Initiatives
Important Links
Subscribe

Disclaimer

Terms of Use

Privacy Policy

© 2024 MDPI (Basel, Switzerland) unless otherwise stated