Textile materials find extensive application in various sectors, including fashion, sportswear, home textiles, medical textiles, automotive textiles, and many more. The combination of their thinness, lightweight nature, flexibility, comfort, a high degree of flexibility. Additionally, they exhibits a porous structure that can be easily scaled up for industrial production [
73]. Furthermore, they demonstrates excellent durability and the capacity to be programmed to achieve desired pore structures makes them highly suitable for a wide range of products and purposes [
74]. Recent advancements in the field of water transmission through textiles materials of varying dimensions have provided novel approaches for the development of floating structures aimed at water evaporation. These include techniques such as utilizing hanging of (woven, non-woven, knitting) fabrics, composite [
41] and electro-spun membranes [
3]. However, this technique involves suspending or hanging fabric materials over a water surface. The fabric acts as a medium for water transmission and evaporation. As water molecules evaporate from the surface, they pass through the fabric, allowing continuous evaporation. The structure of the fabric provides a large surface area for evaporation, enhancing the efficiency of the process. However, the following unique features of the textile materials render them highly promising for solar interfacial evaporation: (i) Fabrics have a textured and rough surface, which enhances their light-absorption abilities. The roughness increases the surface area available for solar radiation absorption, allowing for efficient conversion of solar energy into heat. (ii)Textile materials typically have high porosity and a significant surface area. These characteristics provide an extensive evaporation area, allowing for a larger interface between the liquid and the surrounding air. Additionally, the porosity of textiles creates multiple pathways for the steam to escape, reducing the chances of re-condensation. (iii)Textile materials are known for their exceptional flexibility and robust mechanical strength. They can be easily manipulated and shaped into desired configurations, allowing for the creation of portable and scalable devices. (v)Fabrics are typically cost-effective and readily available materials. The affordability of textiles ensures that the technology can be more accessible and economically viable for widespread implementation, especially in areas with limited resources [
54,
75]. Moreover, Textile materials possess a wide range of raw ingredients, a diverse array of adaptable manufacturing methods, and a high degree of flexibility [
54].
2.1. Woven Fabrics:
Woven technology is usually applied to produce woven fabrics through the systematic interlacing of warp and weft threads, resulting in fabrics that exhibit favorable attributes such as high tensile strength, resilience to wear and tear, dimensional stability, and a dense structure [
54]. Textile products possess a modifiable structure and contains micronized pores, enabling the effortless cleansing of filthy garments. Additionally, these fabrics exhibit commendable longevity, facilitating the effective elimination of impurities [
79]. However, cotton has become known as the primary natural fiber utilized in the textile industry due to its inherent characteristics such as natural softness, significant hygroscopicity, exceptional wear comfort, and skin-friendly properties [
80]. By employing a practical textile weaving method, Zhang Q. et al [
75] presented a ISSG device composed of a blend of carbon fiber and cotton yarn
Figure 5 (a, b). This device has remarkable capabilities in generating solar steam, owing to the carbon fiber's reliable and efficient light-absorbing properties, as well as the unique structure of the fabric. The manipulation of woven fabric design has the ability to control the levels of light absorption and amount of water within the cloth. Under 1 sun light, the modified fabric demonstrates a notable efficiency rate of 1.87 kg m
-2 h
-1 and evaporation efficiency of 83.7%. An all-encompassing and expansive apparatus, equipped with anti-salt clogging capabilities, may be readily achieved through the manipulation of warp thread count and weft thread width. The fabric that has been constructed exhibits considerable promise in the realm of obtaining cost-effective purification of seawater and other forms of wastewater. Consequently, it offers a novel avenue for the advancement of solar interfacial evaporators that are characterized by their high efficiency, scalability, and stability.
Using a conventional loom, Li Y. et al. [
45] created a 3D hierarchical tree-shaped biomimetic flax fabric (TBFF)
Figure 5 (c). The design comprised a float layer, a basket weave layer, and a plain weave layer. The fabric exhibited vertical water transport properties along the uninterrupted warp strands. Subsequently, the TBFF that was acquired underwent a one-step manufacturing process to produce polydopamine-polypyrrole hybrid (PDA-PPy) nanofibers with more surface space and enhanced hydrophobicity. However, the fabricated design demonstrates an ordered structure of micro-capillary porosity within the fibers and macro-interlaced pore spaces across the warp and weft threads. This unique design enables the system to display spectrum light absorption, efficient water supply, a wide evaporation area, and easy steam escape. Hence, the interconnected water transport pathways established by TBFF-PDA-PPy demonstrated a notable evaporation rate of 1.37 kg m
-2 h
-1, with a solar energy transformation performance of 87.4% when subjected to 1 sun irradiation. Due to its straight forward fabrication method, cost-effectiveness, and potential for scalability in manufacturing, the device has promise for facilitating widespread implementation in water filtration and saltwater desalination.
Additionally, a novel approach to fabric draping that involves the separation of the evaporation interface from the bulk water is designed by Gao C. et al [
17]. However, the drape fabric is a coated by a mixture of carbon black (CB) and crosslinked sodium alginate (SA) onto ramie fabric (CSRF). The CSRF exhibited an evaporation rate of 1.81 kg m
-2 h
-1 and an efficiency of 96.6% when subjected to 1sun. Furthermore, manipulating yarn fineness in the fabric create an adjustable water supply system, thereby optimizing energy distribution. This study presents a novel approach to designing and optimizing solar evaporation systems, showcasing significant promise for practical implementation.
Composite fabric combines two or more fibers or materials to create a single fabric with improved qualities. The blended fabric's combination of materials enables the effective utilization of each component's capabilities, leading to a fabric that exhibits enhanced performance qualities. Wang Y. et al [
58] constructed a novel composite material of MXene, carbon nanotubes, and cotton fabric using a layer-by-layer assembly technique
Figure 6 (a). This fabrication aimed to develop a material capable of ISSG for purifying textile effluent. The device significantly enhanced optical absorption, light-to-thermal conversion, and water transport capabilities due to its significant interfacial contacts. Under1solar illumination, the evaporation rate for pure water is 1.35 kg m
−2h
−1, while for textile wastewater, it exceeds 1.16 kg m
−2h
−1 with an evaporation efficiency of 88.2%. These values are higher than those observed in the prior research for fabric-based composites. Reducing the amount of organic-inorganic pollutants in condensed fresh water is a crucial aspect that is often overlooked but holds significant importance in practical applications. In addition, the reusability test and outdoor experiment were conducted to showcase the practical application of the photothermal features. Furthermore, the findings of this study indicate that the composite material possesses superior performance and durability, as well as a straightforward fabrication procedure. These characteristics render it a promising option for wastewater purification using solar evaporation. A three-dimensional (3D) ISSG device in the shape of a cone is developed by He M. et al [
81]. However, the device is consisted cotton fabric coated with vertical polypyrrole nanowires (VPPyNWs)
Figure 6 (b). However, the polypyrrole (PPy) microstructure enhances solar energy absorption by facilitating simultaneous reflections between the vertically aligned PPy nanowires (VPPyNWs). The overall architecture of the 3D evaporator is characterized by an increased surface area, which promotes efficient energy harvesting, a comprehensive pathway for water supply, and an open structure that facilitates vapor diffusion. The 3D VPPyNWs-fabric-based SSG, obtained to demonstrate its feasibility, exhibits a rapid rate of water evaporation 2.32 kg m
−2 h
−1. Additionally, it showcases a high solar absorption performance of 97% and a solar-to-vapor conversion efficiency of 98.56% when subjected to an energy density of 1 kW m
−2. Furthermore, the SSG can be effectively utilized in diverse water conditions, such as seawater, dye wastewater, and acidic and alkaline wastewater. The effective use of solar energy can be significantly enhanced by implementing a high-performance evaporator incorporating a 3D macro- and structural design. This innovative approach presents a promising opportunity for improved solar energy utilization.
A cost-effective and reusable SSG device fabric based is successfully fabricated by Kou H. et al [
34] via applying carbon nanotube (CNT) based ink to conventional cotton fabrics. However, the cotton fabrics colored with CNT, demonstrate significant optical absorption within the wavelength range of 250–2500 nm, resulting in a total solar absorption efficiency of 95.7%. However, with utilizing polystyrene (PS) foam as the thermal insulator, the cotton-carbon nanotube fabrics with insulating properties demonstrate a notable evaporation rate of saltwater 1.59 Kgm
−2 h
−1. Additionally, the apparatus possesses the capability to undergo cleaning and recycling processes through the elimination of the salts that are generated. Following evaporation, the liquid is effectively removed using a straightforward hand-washing procedure. This study demonstrated the feasibility of achieving cost-effective, highly efficient, and large-scale seawater desalination using solar irradiation.
Hydrophilic fabrics are designed to quickly wick away moisture from the skin, spreading it across a larger surface area to enhance evaporation and promote a dry and comfortable feeling. However, a highly hydrophilic, linear, and durable copper-based metal-organic framework (Cu-MOF) is designed by Wang J. et al [
82] an absorber coating is securely attached to the surface of a commercially available textile material through the utilization of a sputtered copper film as a bonding layer
Figure 7 (a). However, the Cu-MOF photothermal fabric based demonstrated effective prevention of salt formation on its upper surface, even when exposed to a salinity of 9.5 wt% for over 12 hours during evaporation. This can be attributed to the CMPT's exceptional capillary effect and strong water-pumping performance. The CMPT, characterized by its exceptional light absorbance (95.9%) resulting from the distinctive hierarchical structure of Cu-MOF that enhances light trapping, and its excellent air permeability, demonstrated a significant evaporation rate of 1.52 kg/m
-2 h
-1 under 1 solar irradiation. The CMPT has a remarkable structural design, resulting in a high degree of adaptability, exceptional mechanical strength, and superb chemical stability even in demanding conditions. The study introduces an easy and uncomplicated method for surface immobilization of MOF coatings on textile fibers. This method has potential practical applications in the development of portable solar steam generators. In another study done by Song L. et al [
31] an innovative method is used for developing an effective ISSG using linen fabric with candle soot
Figure 7 (b) . The system combines broadband light absorption, super-hydrophilicity, and an exceptional transition layer of water between a solar evaporator and an insulating material. This design aims to optimize the temperature control and water supply synergistically. By integrating improved energy management techniques and ensuring an ample water supply, the ISSG that has been developed demonstrates a commendable evaporation rate of 1.44 kg m
−2h
−1 and a high efficiency of conversion. The solar irradiation of 1 sun resulted in a solar-to-thermal conversion efficiency above 90% in salt water with a concentration of 20 wt %. The study has the potential to introduce a novel and straightforward approach to the water purification field.
In a study done by Peng H. et al [
83], a new device of fluidic evaporator is developed, which exhibits asymmetry and enables edge-preferential crystallization. The device facilitates gravity-assisted salt collection and drenching-induced electrokinetic power generation, it is fabricated by spreading TA-MoS
2 nanosheets unevenly on a UIO-66-NH
2-modified PAN fabric as shown in
Figure 8 (a). The system utilized self-manipulated saline water transport to derive benefits, it effectively isolates the crystallized salts from the evaporation surface, facilitating uninterrupted vapor generation and salt extraction for 60 hours in sun desalination processes involving saline solutions with a concentration of 7.5 wt%. This wet fabric evaporator achieves a sustained voltage generation of 0.568 V solely through saline-drenching by utilizing the established gradient electric double layers in asymmetric nanochannels. In addition, the evaporator exhibits a high capacity for effectively removing organic pollutants, with minimal impact on both the water evaporation and power generation rate, even after 60 hours of continuous operation and 30 cleaning instances with an evaporation rate of 1.36 kg m
−2h
−1 and a high efficiency of conversion about 89.2%. This study showcases a scalable multifunctional asymmetric solar evaporator that enables continuous seawater desalination, facilitating salt harvesting and electricity production. Furthermore, it contributes to the progress of adaptable and environmentally friendly applications in useful seawater desalination, specifically to recover resources, power generation, and storage.
The fabrication of self-floating Janus cotton fabric coated with a polyester woven fabric, which can reject salt, has been effectively designed by Gao S. et al [
84] for ISSG system
Figure 8 (b). The device with controlled soot deposition exhibit solar absorption properties and the necessary superhydrophobicity to enable flotation on water, the Janus evaporator demonstrates a sustained evaporation rate of 1.37 kW m
−2 h
−1 and achieves an efficiency of 86.3% when subjected to 1 sun irradiation. Furthermore, it exhibits satisfactory performance under conditions of minimal intensity and tilted radiation. The foldable Janus absorber, which boasts a cost of less than
$1 per square meter, exhibits great potential as a portable solar vapor generator.
Drawing inspiration from the Janus water absorption observed in lotus leaves, Qin Z. et al [
85] developed a bio-inspired combination consisting of cotton fabric supplemented with carbonized carrot powder (CC powder) and coated with Nafion on one side (cotton cloth-NCC). This system has been designed to achieve enhanced efficiency in SSG. The utilization of CC powder in cotton fabric-NCC serves as a means to enhance light absorption, hence achieving a heightened level of light absorption. Simultaneously, the hydrophilic nature of the cotton cloth facilitates effective water transport. In the interim, applying Nafion coating creates a Janus architecture with hydrophobic and hydrophilic properties. This structure serves the dual purpose of regulating water supply and inhibiting salt deposition, even when exposed to high-concentration salt solutions. The cotton cloth-NCC material has undergone further processing to form a waved structure, resulting in w-cotton cloth-NCC. This modification aims to enhance the surface area available for water evaporation and obtain a high light absorption level, specifically reaching 95%. When exposed to solar irradiation, the utilization of w-cotton cloth-NCC results in a water steam generation rate of 1.88 kg m
−2 h
−1 and a saltwater evaporation rate of 1.52 kg m
−2 h
−1. In addition, the w-cotton cloth-NCC has a notable efficacy in purifying sewage. It effectively eliminates Escherichia coli, achieving 100% removal while demonstrating a high removal rate of 98.3% for Rhodamine B. The methodology proposes a straightforward technique for fabricating a hydrophobic-hydrophilic Janus solar steam evaporator that is characterized by excellent efficiency, inexpensiveness, environmentally friendly operation, and long-term stability. This innovative design exhibits significant potential for use in various fields, including environmental purification and photothermal conversion. Additionally, a novel ISSG device was developed by Wang K. et al [
86] by using thermally-treated pre-oxidized polyacrylonitrile fibre fabric combined with carbonized polyaniline nanowires (ECFC/CPANW) as shown in
Figure 9 (a). However, the system exhibits several advantageous characteristics, including low thermal conductivity, efficient absorption of solar radiation across a wide range of wavelengths, favorable hydrophilic properties, and excellent water transport capabilities. The results showed a remarkable vaporization efficiency of up to 93.7% with an evaporation rate of 1.43 kg m
−2 h
−1 when subjected to 1 sun irradiation. Hence, using cost-effective, stable, and environmentally friendly photo-thermal conversion materials holds significant potential for real-world use in water purification processes.
A novel composite membrane of MXene, carbon nanotubes, and cotton fabric is fabricated by Wang Y. et al [
58] by using a layer-by-layer construction technique as ISSG device
Figure 9 (b). Due to its robust surface contacts, the hybrid fabric significantly enhanced optical absorption, light-to-thermal conversion, and water transport capabilities. The evaporation rate for water is found to be 1.35 kg m
−2h
-1, while for textile wastewater, it exceeds 1.16 kg m
−2h
−1 under 1 solar illumination. In addition, the reusability test and outdoor experiment were conducted to showcase the photothermal characteristics of the material when implemented in real-world scenarios. The results indicate that the combined material possesses favorable characteristics such as excellent performance and durability, as well as a straightforward fabrication technique. Thus, it holds promise as a viable option for wastewater purification by solar-evaporation methods.
Peng H. et al [
69] presented a novel approach to purify seawater and power production by developing a one-way asymmetrical nanofluidic photothermal evaporator. The design of this evaporator is inspired by the water and solute transportation in plants, specifically through the transpiration process. The fabrication process involves the in-proportion deposition of photothermal MXene nanosheets on a hydrophilic cotton fabric. However, the cotton fabric pump facilitates the linear transportation of saline solution, allowing for self-operating salt rejection and stable steam generation in the evaporator. Additionally, forming an asymmetric double electrode layer within MXene nanochannels under the drenching state enables continuous electric power generation. The solar-induced evaporation rate and voltage generation achieve a value of 1.38 kg m
-2h
-1 with an efficiency of 83.1% and 363 mV, respectively, when exposed to 1 sun irradiation. Significantly, the aforementioned nanofluidic system exhibits minimal degradation in function following 30 hours of usage and undergoing 15 washing cycles. This observation underscores its exceptional stability and capacity for repeated use. The straightforward design of the asymmetric nanofluidic photothermal system presents potential opportunities to expand sustainable freshwater and electric power generation.
Carbon fibers derived from two types of animal silks, namely Bombyx mori (B. mori) silk and Antheraea pernyi (A. pernyi) silk, are fabricated by Qi P. et al [
87] by using a single-step heating process on a massive scale without the need for any additives or activation procedures. The carbon fibres and yarns possess both electrical conductivity and mechanical strength. To enhance the utilization of carbonized silks, we proceeded to interlace them with cotton yarns, resulting in the production of composite fabrics featuring diverse patterns
Figure 10 (a-e). The results verified the benefits associated with using hybrid fabrics, including enhanced light absorption, increased surface area, and hierarchical liquid transfer routes. These advantageous characteristics make these fabrics suitable for applications such as SSG for desalination and sewage treatment. Furthermore, it was observed that these conductive carbon fibers can be organized into fluidic nano-generators, enabling the generation of electrical energy by the movement of water.
Conventional photo-thermal materials primarily address concerns related to energy efficiency and multipurpose use. However, the absence of adjustable, affordable, adaptable, and washable characteristics significantly hampers their transition from laboratory settings to industrial applications. The achievement of enhanced energy efficiency is of great importance because of the limited utilization of spatial volume in traditional 2D evaporators. Consequently, there is a strong need for the advancement of customizable and programmable 3D designs. However, Xiao P. et al [
88] fabricated a functional photo-thermal fabric that draws inspiration from conventional sewing techniques. The substance exhibits exceptional scalability, washability, and affordability. It enables the creation of tunable and programmable 2D/3D structures, facilitating efficient water extraction from liquid and solid mediums in both in-plane and out-of-plane directions. An in situ adjustable oxy polymerization approach was used to fabricate cotton fabric modified with polypyrrole (PPy) due to the favorable photo-thermal properties, stability, and effective contacts exhibited by PPy with fibrous cotton
Figure 10 (f). The device demonstrates a straightforward and robust method for synthesizing a large-area PPy-modified cotton (PMC) fabric. Moreover, the textiles possess commendable attributes such as sewability and editability, enabling the customizable incorporation of these functional PMC building blocks into 3D system to achieve highly effective out-of-plane solar vaporization. The 3D design can effectively integrate photo-thermal textiles into various surroundings, enabling efficient purified water extraction, even from a sandy substrate.
The fabrication of Janus ink/urushiol-modified cotton fabric was effectively designed by Bai W. et al [
89]
Figure 11 (a, b), resulting in the development of a fabric with distinct hydrophilic and hydrophobic properties. The Janus fabric exhibited exceptional characteristics in terms of water transportation, mechanical strength, thermal conductivity, and photothermal conversion efficiency. When subjected to simulated solar radiation, the temperature of the Janus cloth rose to 85 ◦C for 2 minutes. Furthermore, apparatus exhibited a notable conversion performance of 94.3% alongside a remarkable evaporation rate of 1.64 kg m
− 2 h
− 1 with an adequate resistance to UV light and pH levels and a high capacity for rejecting salt in concentrated salt solutions. The system has shown significant efficacy in the purification of wastewater that contains heavy metals and organic dyes. A fabric that possesses many functions, including integrated ISSG and personal thermal control, offers a sustainable solution for addressing challenges related to water shortages and cold stress is designed by Du H. et al [
90] by combination of graphene oxide photothermal absorber and low-cost hydrophilic Tencel fiber as water supplier
Figure 11 (c). The regulation of photothermal conversion, water supply, and moisture diffusion capabilities can be achieved through the modification of loading, spinning, and twisting parameters. The fabrics that have been combined with whole-yarn-section photothermal capability demonstrate a noteworthy average evaporation efficiency of 90.4% and an impressive evaporation rate of 1.33. The exceptional cost-effectiveness of 222 g h
−1 $−1 and the durability of 20 washing cycles and 15 operation cycles contribute to the great practicality of this device. In general, the GOT fabric offers a tailored solution for individuals engaging in outdoor activities, requiring garments that offer breathability and insulation, as well as portable devices for accessing clean water.
A novel approach to boost freshwater production by integrating Janus fabric with thorough thermal control in a reversed ISSG is conducted by Gao C. et al [
91]. However, an inexpensive Janus fabric, which incorporates recycled cotton fabric, is manufactured by applying a layer of carbon black@silicone on the top side using a straightforward and flexible pre-wet coating technique
Figure 12. The Janus fabric possesses effective sealing capabilities that contribute significantly to the prevention of upward vapor formation, hence minimizing optical loss. Consequently, these characteristics of the Janus fabric contribute to the enhanced collection of freshwater in the distillation process. The Janus fabric-based interfacial solar distiller demonstrates a high level of sunlight absorbance, measuring at 98.0% and remarkable performance, with a water production of 1.17 kg m
− 2h
− 1 and an efficiency of 78% when exposed to one sun (1 kW m
− 2) illumination. The study introduces an innovative design for a high-performance interfacial solar distillation system, which has the capability to be implemented on a large scale and at an affordable rate for industrial production purposes.
2.2. Non-Woven fabrics:
Nonwoven fabrics are produced by aligning or haphazardly arranging staple fibers or filaments to create a fibrous network, which is subsequently strengthened through mechanical, thermal, or chemical processes, they has emerged as a promising and economically viable alternative for ISSG. This can be attributed to its numerous benefits, including the availability of copious raw materials, a straightforward manufacturing method, and the potential for excellent efficiency [
54].
Sun S. et al [
30] fabricated a carbon black (CB)-polydopamine composite non-woven fabric
Figure 13 (a). This method sought a cost-effective and scalable PDA/CB@PP composite. In situ PDA polymerization and CB dip-coating were used to make the fabric. A hierarchical framework on the fiber's outermost layer and CB and PDA synergy produced high light absorbance (>95%), superhydrophilicity, and energy conversion efficiency. The experimental one-way fluidic PDA/CB@PP photothermal-based solar steam evaporator had a 1.68 kg m
-2h
-1 evaporation rate and 91.5% solar steam efficiency. PDA/CB@PP cloth purifies waters well despite salt. The hydrophilic porous fabric retains water channels and ensures a steady water supply. Additionally, the PDA/CB@PP fabric effectively treats heavy metal and chemical dye-polluted wastewater.
A solar evaporator that remains in a perpetual state of flotation is constructed by Zhu Y. et al [
37] through the application of multiwall carbon nanotubes onto a bicomponent nonwoven material consisting of polypropylene/polyethylene core-sheath fibers
Figure 13 (b). The all-fiber structure exhibits a high degree of porosity and ultra-lightness, accompanied by a substantial specific area. The design incorporates features such as enhanced water evaporation efficiency and interconnected passages to facilitate the effective escape of vapor. Additionally, the material should possess a low thermal conductivity in order to minimize heat dissipation. The water transport characteristics of the nonwoven material facilitate its ability to generate a pumping action autonomously. The relationship between water supply and loss has the potential to expedite the rate of water evaporation of 1.44 kg m
-2h
-1 with evaporation efficiency of 89.7% under 1 sun. The fabrication process involves the utilization of inexpensive resources and the implementation of industrialized techniques, resulting in the production of the final product.
The phenomenon of changeable texture and porous clothing being susceptible to pollution is widely acknowledged. However, it is commonly observed that such clothing may be effectively cleansed to eliminate any contaminants, while maintaining their original color and shape without any discernible alterations. However
, Zhu B. et al [
79] designed a washable, stretchable carbon-nanotube-embedded polyacrylonitrile nonwovens fabric using electrospinning technology. The wet fabric has a photo absorption efficiency of 90.8% and high photoabsorption in the 350-2500 nm region. The cloth coated on polystyrene foam had shown a high seawater evaporation rate of 1.44 kg m
−2 h
−1 under simulated sunlight (1.0 kW m
−2). Simulations of high saltwater concentrations reveal solid salt deposition on fabric surfaces, leading to a significant decline in evaporation rate. The washing technique has minimal impact on fabric shape, photoabsorption, and evaporation, indicating longevity. The use of washable fabrics and parallel PS foams allows for the construction of large-scale outdoor evaporation devices, enabling successful desalination of seawater under natural sunlight.
A nonwoven photothermal cloth with exceptional stability, flexibility, and washability is fabricated by Jin Y. et al [
41] via the process of electrospinning technology. The aim is to enhance the efficiency and longevity of solar steam evaporation. The fabric comprises polymeric nanofibers serving as the matrix, with inorganic carbon black nanoparticles embedded inside the matrix to function as the light-absorbing component. The photothermal fabric, which has been enhanced with an optimum carbon loading, exhibits a highly desirable characteristic of being black underwater. This fabric can absorb 94% of the sun spectrum, resulting in an impressive solar energy use efficiency of 83% within the process of pure water evaporation. Due to its unique composition and geometry, the fabric exhibits a characteristic resistance to photothermal component loss. It demonstrates exceptional flexibility and mechanical strength, as well as chemical stability in a wide range of challenging environments, including strong acids, alkaline substances, organic solvents, and saline water. The textile material can undergo hand-washing for over 100 cycles without experiencing performance degradation with evaporation rate 1.24 kg m
−2 h
−1 and evaporation efficiency 83%. This characteristic presents a promising approach for effectively removing fouling agents in real-world applications such as solar steam generation and distillation operations. In a previous study done by Fang Q. et al [
71] a novel ISSG device with an exhibited exceptional light-thermal properties is designed by using activated carbon fiber fabric (ACFC) with tiny architectural structures
Figure 14 (a, b). However, Under optimal conditions, using cotton fiber nonwoven fabrics (CFNF) in a water supply system can significantly increase the evaporation rate, reaching 1.59 kg m
−2 h
−1. Additionally, this system exhibits an impressive conversion performance of 93.3% when exposed to 1 Sun. The significance of achieving optimal alignment between water supply and vapor evaporation is underscored in maximizing heat utilization and enhancing the efficiency of solar desalination processes. Furthermore, the additional water supply pathway facilitated by CFNF effectively mitigates salt fouling by regular removal of salt deposits, ensuring the long-lasting performance of the self-cleaning solar steam generating system. Therefore, the ACFC+CFNF arrangement demonstrates significant potential for utilization in permanent and extremely effective solar desalination.
The continual problem lies in achieving a balance between the expense and freshwater output. In order to address these issues, discrete waste carbon fibers are organized into a yarn that can be stretched and compressed by Wang J. et al [
73]. This yarn is then processed for use in a fabric evaporator, which enables the creation of solar steam. This is achieved through the utilization of two primary textile technologies: blended yarn spinning and multibeam weaving
Figure 14 (c, d). In order to enhance the evaporation efficiency of the photothermal device, a bionic fabric structure inspired by the aquatic plant Pistia has been devised with the aim of minimizing heat dissipation and maximizing the use of material. The capacity of the system is enhanced by leveraging the porous structure and gradient capillary effect of the evaporator. By positioning the photothermal component 3.2 cm above the water surface, the evaporation efficiency is significantly increased from 52.70% in its initial state to 88.70% with evaporation rate 1.50 kg m
-2h
-1 under the influence of 1 sun (1 kW m
−2). In conjunction with the affordable nature of waste carbon fiber and well-established textile technologies, the overall price of raw materials for the device is decreased to USD 3.54 m
2. This research presents potential opportunities for an economically viable and scalable method of generating steam from solar power.
2.3. Electro-spun membranes:
Electro-spun membranes are commonly manufactured using the electrospinning technique, [
92] it is a highly adaptable textile technique for producing flexible nano/micron fibers membranes [
5,
93]. It is a process that involves the application of an electric field to create fine fibers from a polymer solution or melt [
54,
66]. Fiber membranes produced through electrospinning exhibit controlled fiber arrangement, elevated porosity, exceptional mechanical characteristics, and a network of interconnected pores. [
94]. Moreover, these fibers have diameters typically in the range of tens to hundreds of nanometers, resulting in a high surface area-to-volume ratio and unique properties such as customizable fiber dimensions and pore architectures [
55,
95], rendering those promising materials for wide range of applications such as; filtration medium with elevated permeability, water treatment [
96]. However, recently, numerous solar vapor generators utilizing electrospun nanofibers and nonwoven fabrics have been created within the domain of solar vapor generation [
5,
97]. A cost-effective, buoyant, long-lasting, and expandable evaporator has been developed, incorporating an exposed nanofiber-based dual-purpose framework to generate solar steam efficiently is designed by Gao T. et al [
98]. The combined bilayer evaporator is constructed sequentially, starting from the bottom with layers of electrospun hydrophobic polyvinylidene fluoride (PVDF) nanofibers, followed by layers of hydrophilic carbon black/polyacrylonitrile (CB/PAN) composite nanofibers
Figure 15 (a, b). The presence of a porous hydrophobic PVDF nanofiber layer can be attributed to its inherent poor thermal conductivity. This layer is a floating support and thermal barrier, mitigating irreparable heat loss. The upper layer of the composite nanofiber, consisting of hydrophilic CB/PAN, has a significant solar adsorption capacity throughout a wide range of wavelengths (250-2500 nm), reaching an impressive efficiency of 98.6%. This characteristic enables efficient conversion of solar irradiation into usable heat energy. The CP/P evaporator, when completed, demonstrates a noteworthy solar energy conversion efficiency of 82.0% and evaporation rate of 1.2 kg m
−2 h
−1 when subjected to 1sun illumination. The polymer-nanofiber-based evaporator, which exhibits cost-efficiency, remarkable adaptability, resilience, and capacity, shows significant potential for real-world use in water desalination and disinfection.
Using electrospinning and laser treatment processes, Chen Z. et al [
60] fabricated a photothermal membrane with a three-dimensional (3D) structure. This membrane is composed of laser-induced graphene (LIG) and polyimide (PI) and exhibits significant porosity
Figure 15 (c). 3D configuration of the LIG/PI membrane enhances the surface area available for evaporation and mitigates the energy dissipation resulting from the scattering of light. The LIG/PI membrane demonstrates a notable evaporation rate of approximately 1.42 kg m
−2 h
−1, and a significant solar thermal conversion efficiency of approximately 92.55%. It exhibits long-term evaporation stability in a high-concentration saline solution under one sun illumination, thanks to incorporating an insulating layer and water flow pathways. This durable photothermal membrane has the potential to offer valuable insights for the development of interfacial evaporation systems that are both quick and efficient.
The utilization of a solution-electrospun nanofiber membrane has been recognized as a highly suitable framework for solar steam generation. This is attributed to its various advantageous characteristics, including its substantial porosity which facilitates efficient absorption of light, its significant permeability that enables rapid water transport, and its cost-effectiveness, portable nature, and exceptional adaptability, rendering it extremely useful for real-world applications [
99]. However, an effective and flexible fiber membrane of silicon dioxide/carboxylated multi-walled carbon nanotube/polyacrylonitrile (SiO
2/MWCNTs-COOH/PAN) was fabricated by Qu Q. et al [
100] by using electrospinning
Figure 16 (a, b). Subsequently, an interfacial water evaporator was constructed by affixing it onto a filter paper substrate, employing insulating polystyrene (PS) foam as the supporting substance, and utilizing cotton yarns for water conveyance. The design offers multiple benefits, including preventing heat dissipation to the bulk water and assuring high evaporation effectiveness. The composite fiber membrane demonstrated a high evaporation rate of 1.28 kg m
−2 h
−1 and an impressive photothermal conversion efficiency of 82.52% when exposed to 1 solar irradiation (1000 W m
−2). In addition, it is worth noting that the composite fiber membrane that was created exhibited remarkable stability in evaporation rate and efficiency, even after undergoing 20 consecutive evaporation cycles. Therefore, the interfacial water evaporator developed in this study shows exceptional photothermal conversion efficiency, making it a highly viable option for solar-powered saltwater desalination. Additionally, Ag nanoparticles adorned MXene nanosheets/polyacrylonitrile (Ag@MXene/PAN) nanofiber-based evaporators with a high efficiency, multipurpose, and unidirectional SSG device is fabricated by Liu H. et al [
99]
Figure 16 (c). However, the combination of Ag nanoparticles and MXene nanosheets exhibits several advantageous properties, including enhanced broadband light absorption and heat generation and improved catalytic and antibacterial capabilities. In addition, the membrane possess the beneficial properties of elasticity and foldability, which allow for creating a three-dimensional evaporator with enhanced evaporation surface area and optimal light absorption. The developed evaporator exhibits steady evaporation rates throughout a broad range of incident angles, from 30° to 150°. Under 1 sunlight, the maximum evaporation rate approaches 2.08 kg m
-2 h
-1, significantly higher than the state-of-the-art solution-electrospun nanofiber-based evaporators. The combination of structural adaptability, outstanding efficiency, and multi-functionality renders the developed nanofiber-based evaporator extremely desirable for producing clean water in practical uses.
Plasmonic silver nanoparticles (Ag NPs) as photothermal coatings and electrospun polyacrylonitrile (PAN) nanofiber membranes as substrates are utilized by lin Y. et al [
101]. The diameters of Ag NPs and the light-absorption capabilities of the associated nanofiber membrane were controlled by altering the volume ratios of glucose and silver ammonia solution. Consequently, the Ag@PAN nanofiber membrane exhibited a notable light-absorption efficiency of 92.8% within the wavelength range of 280–2500 nm. Under irradiations of 1 sun the evaporation rate and evaporation efficiency were1.34 kg m
-2 h
-1 and 76.0, respectively. The plasmonic nanofiber membrane demonstrated sustained operational stability, as seen by its consistent solar vapor generation capability during a series of 10 cycle tests, without any observable degradation. This research establishes a foundation for the conceptualization and creation of plasmonic nanofiber membranes with the potential to function as efficient interfacial solar vapor generators. In recent study, An aerogels with a hierarchical pore structure using an environmentally friendly bonding and freeze-drying process developed by Liu Y. et al [
97] by using electrospinning technique. These aerogels were composed of electrospun nanofibers made from a blend of polyacrylonitrile and carbon nanotubes (PAN/CNTs), it is developed by combining the synergistic photothermal effect of PDA and CNTs, which significantly increased light absorption efficiency, reaching 94.8%. The device demonstrated a rapid evaporation rate of 2.13 kg m
-2 h
− 1 and a high solar-vapor conversion efficiency of 94.5% under one sun, surpassing the majority of previously published solar vapor generators based on electrospun nanofibers. The aerogel described herein offers a flexible, environmentally sustainable, and economically viable solution for producing clean water.
Xu W. et al [
102] studied showcases the efficacy of a foldable Janus absorber, manufactured by a sequential electrospinning process, in facilitating reliable and effective solar desalination. The distinctive architecture of Janus is leveraged to separate the processes of steam generation, namely solar absorption and water pumping, into distinct layers. The topmost layer consists of a hydrophobic coating of carbon black nanoparticles (CB) embedded in polymethylmethacrylate (PMMA), facilitating light absorption. Meanwhile, the lower layer comprises a hydrophilic polyacrylonitrile (PAN) responsible for the water-pumping mechanism. Hence, salt deposition exclusively occurs inside the hydrophilic PAN layer, facilitated by the continuous influx of water, leading to its rapid dissolution. The Janus absorber exhibits a notable level of performance, reaching 72%, which surpasses the performance of many prior absorbers. Additionally, it shows a consistent water output of 1.3 kg m
–2 h
–1 over 16 days under 1-sun conditions, a feat that most previous absorbers have not accomplished. The flexible Janus absorber exhibits a distinctive framework attained by an adjustable technique. This absorber is an effective, reliable, and easily transportable solar steam generator specifically designed for direct sun desalination.
The demonstration of a membrane composed of a hybrid nanofibrous hydrogel-reduced graphene oxide (NHrG) is studied by Zhang L. et al [
103] by using elecrospinning technology. The results providing evidence for the existence of intermediate water within the permeable membrane through the observation of the vaporization enthalpy in relation to the saturation of the membrane. Moreover, this finding highlights the significant influence of intermediate water vaporization in reducing the overall vaporization enthalpy. The decreased enthalpy value, in conjunction with many other aspects, such as the enhanced light absorption efficiency facilitated by reduced graphene oxide (rGO) and the formation of a porous hydrophilic network produced by electrospun hydrogel nanofibers, contributed to the development of a very effective solar-driven interfacial evaporator. The NHrG membrane exhibited a maximum evaporation rate of 1.85 kg m
−2 h
−1, accompanied by a notable energy conversion efficiency of 95.4% when subjected to 1 sun irradiation. Furthermore, the evaporator demonstrated exceptional desalination efficacy when employed for the treatment of unpolluted seawater, effectively eliminating salt and heavy metal ions.
2.4. Knitting Fabrics:
Knitting is a textile production method that involves creating interlocking loops of yarn or thread using knitting needles or machines. Knitted fabrics have distinct characteristics and are widely used in various applications. However, a cost-effective and adaptable photothermal membrane (PTM) is fabricated by Wan P. et al [
104] from basalt fibers derived from natural basalt by using knitting technology
Figure 17 (a, b). The synthesis of the basalt-fiber PTM involves the processes of fiber formation and heating. Due to its unique chemical composition and structural characteristics, the PTM exhibits exceptional durability and corrosion resistance in challenging conditions, including harsh acids, organic solvents, and alkalis. The investigation focuses on the techniques of water evaporation, with particular attention given to the floating-with-insulator model. This technique shows the least heat dissipation and the fastest rate of water evaporation. The optimization of the basalt-fiber fabric involves the processes of carbonization and vaporization. Through these processes, a vaporization rate of 1.50 kg.m
-2h
-1 and an energy utilization efficiency of 82.5% are attained for the evaporation of clean water. The PTM made from basalt fiber exhibits a notable resistance to efficiency degradation, allowing it to withstand hand washing for a minimum of 30 cycles. The manufacturing method's scalability enables it to cater to commercial demands effectively.
An easily manufactured, cost-effective, and highly reliable solar-driven evaporator is fabricated by Yang Y. et al [
8] by utilizing a dyed cotton towel with a hollow conical shape. After the dyeing process
Figure 17 (c), the reactive dye molecules undergo diffusion into the cotton fabric and establish robust covalent bonds with the fibers. This results in the secure attachment of light-absorbing components onto the substrate. Utilizing a looping pile architecture in towels and an ordered arrangement in yarns facilitates the expansion of the evaporator's surface area. The cotton towel's hollowed cylindrical structure demonstrates a notable capacity to mitigate heat dissipation to the surrounding environment while maintaining its ability to absorb light. The 3D vapor generator indicates an evaporation rate of 1.40 and 1.27 kg m
−2 h
−1 for pure and saline water. Moreover, it offers a dependable approach for addressing practical water sources, including saltwater and dyeing wastewater. Hence, a cost-effective water evaporation system powered by solar energy presents a supplementary method for achieving optimal vapor generation and water purification in real-world scenarios.
Wang F. et al [
47] developed an innovative solar steam generation system utilizing a hollow spacer fabric (HSF) that has been modified by incorporating chitosan and applying a reduced graphene oxide coating onto its outermost layer. The improved BHSF exhibits enhanced efficiency in terms of water transport and mechanical properties due to its porous textile fabric structure, which provides superior thermal insulation. It demonstrates an elastic modulus of up to 733 kPa at a strain of 70% and a low thermal conductivity of 0.08 W m
-1 K
-1. When subjected to sun irradiation with a power density of 1 kW/m
-2, this particular solar generator exhibits an evaporation efficiency of 86% with an evaporation rate of 1.44 kg m
−2 h
−1. The improved BHSF exhibits exceptional resistance to salt, particularly in high saline solutions, due to its distinctive cylindrical structure and the presence of a well-aligned array of large channels measuring 2 mm in size. This distinctive design provides extra pathways with minimal tortuosity, facilitating efficient evaporation. BHSF exhibits promising prospects for the large-scale production of a cost-effective solar still. This solar still possesses exceptional mechanical versatility, physicochemical durability, and a high solar energy conversion efficiency. These attributes make it suitable for various uses, such as power generation, desalination, and steam sterilization.
Pursuing an ecologically sustainable method for acquiring cellulose nanofiber and fabricating an evaporator based on aerogel represents a pragmatic necessity. However, He M. et al [
105] fabricated a novel cellulose hybrid aerogel ISSG that is both stable and green from waste cotton fibers The aerogel composed of polyethyleneimine cross-linked carbon nanotubes and cellulose nanofibers (PEI@CNTs/CNFs), it shows a notable solar steam generation rate of 1.9 kg m
-2 h
-1 with a light a vapor conversion rate of 91.4% when exposed to 1 sun irradiation. Furthermore, the evaporator can ensure consistent and enduring efficiency for solar steam generation even after undergoing extensive long-term testing. In addition, the device can treat many types of wastewater, such as dye sewage, toxic ion wastewater, and seawater. The characteristics above of the cellulose-based composite aerogel provide a highly effective method for solar-powered water filtration, regeneration, and desalination. Regeneration cellulose aerogels (CAs) functionalized with polydopamine (PDA) have been developed by Liu H. et al [
28] by using an environmentally friendly and practical approach to facilitate the production of clean water. By initiating the polymerization of PDA on the surface, a material known for its remarkable photothermal conversion capabilities and water-purifying properties, the result demonstrates a notable light absorption efficiency of 96.5% and an evaporation rate of 2.74 kg m
−2 h
−1 under 1 sun irradiation. In the context of solar steam production, it has been observed that a solar steam generator with an increasing height can absorb energy from the surrounding atmosphere, hence enhancing the process of vapor creation. Renewable cellulose-based aerogels have inherent characteristics that facilitate effective water evaporation. These attributes, together with their cost-effectiveness and recyclability, hold significant potential in mitigating both energy consumption and the environmental impact associated with cotton fabric.