Search Results (55)

Water scarcity is a growing global challenge, intensified by climate change, seawater intrusion, and pollution. While conventional desalination methods are energy-intensive, solar-driven interfacial evaporators offer a promising low-energy solution by leveraging solar energy for water evaporation, with the resulting steam condensed into purified water. Despite advancements, challenges persist, particularly in addressing volatile contaminants and biofouling, which can compromise long-term performance. The integration of photocatalysts into solar-driven interfacial evaporators has been proposed as a solution, enabling pollutant degradation and microbial inactivation while enhancing water transport and self-cleaning properties. This review critically assesses testing methodologies for solar-driven interfacial evaporators incorporating both photothermal and photocatalytic functions. While previous studies have examined materials and system design, the added complexity of photocatalysis necessitates new testing approaches. First, solar still setups are analyzed, particularly concentrating on the selection of materials and geometry for the transparent cover and water-collecting surfaces. Then, performance evaluation tests are discussed, with focus on the types of tested pollutants and analytical techniques. Finally, key challenges are presented, providing insights for future advancements in sustainable water purification. Full article

Titanium dioxide (TiO₂) is a benchmark photocatalyst for environmental applications, but its limited visible-light activity due to a wide band gap and fast charge recombination restricts its practical efficiency. This study presents the development of heterostructured Ag (Au)/MoS₂-TiO₂ inverse opal (IO) films that synergistically integrate photonic, plasmonic, and semiconducting functionalities to overcome these limitations. The materials were synthesized via a one-step evaporation-induced co-assembly approach, embedding MoS₂ nanosheets and plasmonic nanoparticles (Ag or Au) within a nanocrystalline TiO₂ photonic framework. The inverse opal architecture enhances light harvesting through slow-photon effects, while MoS₂ and plasmonic nanoparticles improve visible-light absorption and charge separation. By tuning the template sphere size, the photonic band gap was aligned with the TiO₂-MoS₂ absorption edge and the localized surface plasmon resonance of Ag, enabling optimal spectral overlap. The corresponding Ag/MoS₂-TiO₂ photonic films exhibited superior photocatalytic and photoelectrocatalytic degradation of tetracycline under visible light. Ultraviolet photoelectron spectroscopy and Mott–Schottky analysis confirmed favorable band alignment and Fermi level shifts that facilitate interfacial charge transfer. These results highlight the potential of integrated photonic–plasmonic-semiconductor architectures for efficient solar-driven water treatment. Full article

Metal nanostructure-assisted solar-driven interfacial evaporation systems have emerged as a promising solution to achieve sustainable water production. Herein, we fabricated photothermal films of a bumpy gold nanoshell with controlled shell thicknesses (11.7 nm and 16.6 nm) and gap structures to enhance their photothermal conversion efficiency. FDTD simulation of bumpy nanoshell modeling revealed that thinner nanoshells exhibited higher absorption efficiency across the visible–NIR spectrum. Photothermal films prepared by a three-phase self-assembly method exhibited superior photothermal conversion, with films using thinner nanoshells (11.7 nm) achieving higher surface temperatures and faster water evaporation under both laser and sunlight irradiation. Furthermore, evaporation performance was evaluated using different support layers. Films on PVDF membranes with optimized hydrophilicity and minimized heat convection achieved the highest evaporation rate of 1.067 kg m⁻² h⁻¹ under sunlight exposure (937.1 W/m²), outperforming cellulose and PTFE supports. This work highlights the critical role of nanostructure design and support layer engineering in enhancing photothermal conversion efficiency, offering a strategy for the development of efficient solar-driven desalination systems. Full article

The primary challenge associated with stainless steel in fuel cell operation is its susceptibility to corrosion, which leads to increased contact resistance and subsequent degradation of electrochemical performance. In general, the protective layers have been loaded onto the metal surface by widely used traditional techniques such as physical vapor deposition (PVD), or cathode arc ion plating. However, the above sputtering and evaporation ways require a high-vacuum condition, complicated experimental setups, higher costs, and an elevated temperature. Therefore, herein the achievement for uniform coatings over a large surface area has been realized by using a cost-effective strategy through a complete wet chemical process. The synergistic regulation of two conductive components and a plastic additive has been employed together with the entrapment of a surfactant to optimize the microstructure of the coating surface. The assembly of layered graphite and a polystyrene sphere could maintain both the high corrosion resistance feature and excellent electrical conductivity. In particular, the intrinsic vacant space in the above physical barriers has been filled with fine powders of indium tin oxide (ITO) due to its small size, and the interconnected conductive network with vertical/horizontal directions would be formed. All the key technical targets based on the U.S. Department of Energy (DOE) have been achieved under the simulated operating environments of a proton exchange membrane fuel cell. The corrosion current density has been measured as low as 0.52 μA/cm² (for the sample of graphite/mixed layer) over the applied potentials from −0.6 V to 1.2 V and its protective efficiency is evaluated to be 99.8%. The interfacial contact resistance between the sample and the carbon paper is much less than 10 mΩ·cm² (3.4 mΩ·cm²) under a contact pressure of 165 N/cm². The wettability has been investigated and its contact angle has been evolved from 48° (uncoated sample) to even 110°, providing superior hydrophobicity to prevent water penetration. Such an innovative approach opens up new possibilities for improving the durability and reducing the costs of carbon-based coatings. Full article

Solar-driven interfacial evaporation desalination is regarded as a promising solution to address freshwater scarcity. However, salt deposition remains a significant challenge. While structural designs such as designated deposition sites can control crystallization, the mechanisms of salt precipitation at specific locations are still unclear. In the present work, we designed a three-dimensional conical evaporator using low-cost cellulose paper for efficient solar-driven desalination. This innovative evaporator design achieves controlled salt crystallization by meticulously balancing the rates of salt diffusion and accumulation, thereby directing salt precipitation to a predetermined location approximately 1.4 cm above the conical base. This phenomenon arises from temperature variations across the evaporator’s three-dimensional surface, which induce differences in water surface tension and create favorable sites for salt precipitation. Such a salt management strategy allows for continuous operation for up to 8 h in high-salinity conditions (24.5 wt.%) without compromising performance. Under one sun irradiation, the evaporator demonstrates exceptional performance, with an evaporation rate of 2.54 kg·m⁻²·h⁻¹ and an impressive energy conversion efficiency of 93.7%. This approach provides valuable insights into the salt precipitation mechanism, contributing to the future design of three-dimensional evaporators and innovative salt collection strategies. Full article

An efficient solar water evaporator is an important strategy for addressing the problem of water shortage. Constructing high-performance solar interfacial evaporators through bionic design has become a crucial approach for performance enhancement. Through the study of zebra patterns, it has been found that the black-and-white alternating patterns generate vortices on the surface of the zebra’s skin, thereby reducing the temperature. By utilizing the vortices brought about by the temperature difference, the design of a solar water evaporator is created based on the bionic zebra pattern, so as to improve its water evaporation performance. In this work, green and sustainable wood is used as the base of the evaporator, and the bionic design of zebra stripes is adopted. Meanwhile, the following research is conducted: The wood is cut into thin slices with dimensions of 30 × 30 × 5 mm³, and a delignification treatment is performed. Tannic acid-Fe ions are used as the photothermal material for functionalization. A series of stable patterned water evaporators based on delignification wood loaded with tannic acid-Fe ion complex (TA-Fe³⁺) are successfully prepared. Among them, the wood-based solar water evaporator with 3 mm zebra stripes exhibits excellent photothermal water evaporation performance, achieving a water evaporation rate of 1.44 kg·m⁻²·h⁻¹ under the illumination intensity of one sun. Its water evaporation performance is significantly superior to that of other coating patterns, proving that the bionic design of zebra patterns is effective and can improve water evaporation efficiency. This work provides new insights into the development of safe and environmentally friendly solar interfacial water evaporation materials through bionic design. Full article

Solar-driven interfacial evaporation has emerged as a sustainable and highly efficient technology for seawater desalination, attracting considerable attention for its potential to address global water scarcity. However, challenges such as low evaporation rates and salt accumulation significantly hinder the performance and operational lifespan of evaporators. Here, we present an innovative Janus-structured evaporator featuring distinct operational mechanisms through the integration of a hydrophobic PVDF-HFP@PPy photothermal membrane and a hydrophilic PVA-CF@TA-Fe³⁺ hydrogel, coupled with a unidirectional flow configuration. Distinct from conventional Janus evaporators that depend on interfacial water transport through asymmetric layers, our design achieves two pivotal innovations: (1) the integration of a lateral fluid flow path with the Janus architecture to enable sustained brine replenishment and salt rejection and (2) the creation of dual vapor escape pathways (hydrophobic and hydrophilic layers) synergized with hydrogel-mediated water activation to elevate evaporation kinetics. Under 1 sun illumination, the evaporator achieves a maximum evaporation rate of 2.26 kg m⁻² h⁻¹ with a photothermal efficiency of 84.6%, in both unidirectional flow and suspension modes. Notably, the evaporation performance remains stable across a range of saline conditions, demonstrating remarkable resistance to salt accumulation. Even during continuous evaporation of highly saline water (10% brine), the evaporator maintains an evaporation rate of 2.10 kg m⁻² h⁻¹ without observable salt precipitation. The dual anti-salt strategies—enabled by the Janus structure and unidirectional flow design—underscore the evaporator’s capability for sustained high performance and long-term stability in saline environments. These findings provide valuable insights into the development of next-generation solar evaporators that deliver high performance, long-term stability, and robustness in saline and hypersaline environments. Full article

Solar-driven interfacial water evaporation technology coupled with photocatalytic function is regarded as an emerging approach for treating high-salinity organic wastewater, but it remains challenging to design high-performance solar evaporators with excellent photocatalytic properties. Here, we designed a two-dimensional flexible solar interfacial evaporator with photocatalytic function for the purification of high-salinity organic wastewater. The solar evaporator was prepared by the deposition of Cu-based metal organic frameworks (Cu-MOFs) onto a polyester fabric by solvothermal reaction, during which graphitic carbon nitride was also deposited as carried by Cu-MOFs. The solar evaporator achieves an outstanding evaporation rate of 1.95 kg m⁻² h⁻¹ for simulated seawater (3.5 wt% NaCl) under 1 sun. The evaporator also shows efficient evaporation performance and salt resistance for high-concentration saline water due to its outstanding water transport capacity and efficient light absorption ability. Furthermore, salt ions and organic pollutants can be simultaneously removed from high-salinity organic wastewater by the evaporator due to the synergistic effects of adsorption, the photothermal effect and photocatalytic performance. This study successfully integrated photocatalytic technology with solar-driven interfacial evaporation, extending the multifunctionality of solar evaporators for treating high-salinity organic wastewater. Full article

The global shortage of freshwater resources and the energy crisis have propelled solar-driven interfacial evaporation (SDIE) coupled with photocatalytic technology to become a research focus in efficient and low-carbon water treatment. Graphene-based materials demonstrate unique advantages in SDIE–photocatalysis integrated systems, owing to their broadband light absorption, ultrafast thermal carrier dynamics, tunable electronic structure, and low evaporation enthalpy characteristics. This review systematically investigates the enhancement mechanisms of graphene photothermal conversion on photocatalytic processes, including (1) improving light absorption through surface morphology modulation, defect engineering, and plasmonic material compositing; (2) reducing water evaporation enthalpy via hydrophilic functional group modification and porous structure design; (3) suppressing heat loss through thermal insulation layers and 3D structural optimization; and (4) enhancing water transport efficiency via fluid channel engineering and wettability control. Furthermore, salt resistance strategies and structural optimization significantly improve system practicality and stability. In water treatment applications, graphene-based SDIE systems achieve synergistic “adsorption–catalysis–evaporation” effects, enabling efficient the degradation of organic pollutants, reduction in/fixation of heavy metal ions, and microbial inactivation. However, practical implementation still faces challenges including low steam condensation efficiency, insufficient long-term material durability, and high scaling-up costs. Future research should prioritize enhancing heat and mass transfer in condensation systems, optimizing material environmental adaptability, and developing low-cost manufacturing processes to promote widespread application of graphene-based SDIE–photocatalysis integrated systems. Full article

As an environmentally friendly and clean energy technology, solar-driven interfacial evaporation technology has attracted wide attention. However, organic pollutants can easily pollute distilled water during the evaporation of wastewater. In this work, we report a strategy of N-TiO₂/C solar absorption with a low bandgap (2.33 eV), excellent light absorption ability, and high photothermal conversion efficiency (48.2%). Black N-TiO₂/C was prepared by the sol-gel method in the presence of hexamethylenetetramine as a source of nitrogen and carbon. The simultaneous N doping and C with superior photothermal effect rapidly increased the surface temperature of the material, reduced the recombination rate of electrons and holes, and improved the photocatalytic activity, showing great potential for solar thermal energy conversion. The prepared solar absorbent and polyurethane (PU) were mixed evenly to form a porous N-TiO₂/C/PU (NTCP) foam for purifying water. The evaporator produced clean water at a rate of 1.73 kg m⁻² h⁻¹ under the simulated sunlight of 1 sun irradiation. Meanwhile, the evaporator simultaneously photodegraded methylene blue (MB) and rhodamine B (RhB) underwater at a removal rate > 90%. The bifunctional solar water evaporation device combining photocatalytic and photothermal effects holds great potential for water purification. Full article

A multifunctional paper-based composite of paper coated with a polypyrrole@lignocellulosic slurry (PPy@LS) and carboxymethyl cellulose (CMC) was developed. PPy@LS was prepared via the polymerization of pyrrole onto a lignocellulosic slurry derived from hemp stalks prepared using deep eutectic solvents. The PPy@LS slurry was mixed with the required amount of CMC and vacuum-filtered onto filter paper to fabricate the composite (PPy@LS/CMC). The resulting composite paper exhibited excellent multifunctional properties, including electrical conductivity, photothermal conversion, and antibacterial properties. These properties are stable against external environments, such as water and abrasion, due to the addition of CMC. The electrical conductivity of PPy@LS/CMC varied in the dry (1.6 × 10⁻⁴ S/cm) and wet (4.8 × 10⁻⁶ S/cm) states, suggesting its potential application in humidity sensing. Notably, the PPy@LS/CMC paper achieved significant photothermal activity under light irradiation, as demonstrated by the measured surface temperature exceeding 80 °C in 10 min. Moreover, the composite paper exhibited > 99.9% antibacterial activity against Escherichia coli (Gram-negative) and Staphylococcus aureus (Gram-positive). The combination of the inherent characteristics of filter paper along with the photothermal property of PPy enable the PPy@LS/CMC composite appropriate for solar interfacial evaporation application. These multifunctional composite papers with innovative combinations of properties have great potential for applications in smart packaging, humidity sensing, biomedicine, and solar-driven water purifications. Full article

Water-in-oil microemulsions, as stable colloidal dispersions from quasi-ternary mixtures, have been used in diverse applications, including nanoreactors for confined chemical processes. Their use as soft templates not only includes nanomaterial synthesis but also the interfacial assembly of nanoparticles in hybrid nanostructures. Especially the hierarchical arrangement of different types of nanoparticles over a surface in filament networks constitutes an interesting bottom-up strategy for facile and tunable film coating. Herein, we demonstrate the versatility of this surface assembly from microemulsion dispersions. Transmission and Scanning Electron Microscopy, in addition to UV–Vis Transmittance Spectroscopy, proved the assembly tunability after solvent evaporation under different conditions: the nanostructured films can be formed over different surfaces, using different compositions of liquid phases, as well as with the incorporation of different nanoparticle materials while keeping equivalent surface functionalization. This offers the possibility of adapting different components and conditions for coating tuning on a larger scale with simple procedures. Full article

In recent years, research on interfacial photothermal water evaporation has been thriving. Due to its inherent porosity, exceptional hydrophilicity, and renewable characteristics, wood has garnered significant attention as a material for interfacial photothermal evaporation absorbers. In order to enhance the cellular channels of poplar and improve its water migration capacity, Trichoderma spiralis was selected to inoculate and culture poplar specimens from different sections for 3, 5, and 7 weeks. Simultaneously, a solar radiation intensity of 1 kW·m⁻² was simulated to perform photothermal evaporation tests on the specimens. This validated the water migration capabilities of different sections of poplar treated with Trichoderma spiralis under light and heat exposure. The characteristic changes were analyzed using electron microscope scanning, infrared spectrum analysis, X-ray photoelectron spectroscopy analysis, surface infiltration performance, and automatic specific surface porosity. The results suggested that the moderate degradation of cellulose and hemicellulose in poplar by Trichoderma spiralis could dredge the cell channels and improve the permeability of poplar, particularly with regard to lateral permeability. The maximum photothermal evaporation rate of the poplar specimen reached 1.18 kg m⁻² h⁻¹, while the evaporation efficiency increased to 72.2%. Full article

Mixed matrix lithium adsorbents have attracted much interest for lithium recovery from brine. However, the absence of an interfacial interaction between the inorganic lithium-ion sieves (LISs) and the organic polymer matrix resulted in the poor structural stability and attenuated lithium adsorption efficiency. Here, a novel hollow hemispherical mixed matrix lithium adsorbent (H-LIS) with high interfacial compatibility was constructed based on mussel-bioinspired surface chemistry using a solvent evaporation induced phase transition method. The effects of types of functional modifiers, LIS loading amount, adsorption temperature and pH on their structural stability and lithium adsorption performance were systematically investigated. The optimized H-LIS adsorbent with the LIS loading amount of 50 wt.% possessed the structural merit that the LIS functionally modified by dopamine exposed on both the inner and outer surfaces of the hollow hemispheres. At the best adsorption pH of 12.0, it showed a comparable lithium adsorption capacity of 25.68 mg·g⁻¹ to the powdery LIS within 4 h, favorable adsorption selectivity of Mg/Li and good reusability that could maintain over 90% of lithium adsorption capacity after the LiCl adsorption—0.25 M HCl pickling-DI water cleaning cycling processes for three times. The interfacial interaction mechanism of H-LIS for lithium adsorption was innovatively explored via advanced microcalorimetry technology. It suggested the nature of the Li⁺ adsorption process was exothermic and dopamine modification could reduce the activation energy for lithium adsorption from 15.68 kJ·mol⁻¹ to 13.83 kJ·mol⁻¹ and trigger a faster response to Li⁺ by strengthening the Li⁺-H⁺ exchange rate, which established the thermodynamic relationship between the structure and Li⁺ adsorption performance of H-LIS. This work will provide a technical support for the structural regulation of functional materials for lithium extraction from brine. Full article

Along with the rapid development of society, freshwater shortages have become a global concern. Although existing desalination technologies have alleviated this pressure to some extent, their long-term environmental impact and energy consumption are still questionable. Therefore, it is necessary to find a new effective way for seawater desalination with cleaner energy. Solar-driven interfacial water evaporation technology has the advantages of environmental protection, energy saving, high evaporation efficiency, low cost, and strong sustainability, and is considered one of the most effective technologies to relieve water resource stress. This review summarized the recent advances in carbon-based interfacial photothermal converters focused on the preparation methods of 2D and 3D photothermal absorbers, the potential ways to enhance the efficiency of photothermal conversion. Finally, this paper proposed the challenges and future trends of interfacial photothermal converters. Full article