Advances in Gel-Based Solar Interfacial Evaporators: Advantages, Performance and Applications

Solar interfacial evaporation (SIE) emerges as a pivotal technology for addressing global freshwater scarcity and advancing sustainable development. Gel materials, distinguished by their inherent hydrophilicity and porous architecture, have garnered significant interest for SIE applications. First, this review elaborates on the compelling advantages of gels for SIE, stemming from their low thermal conductivity, reduced evaporation enthalpy, good hydrophilicity, tunable porous structure, adjustable mechanical properties, facile processability, and multifunctional integration capabilities. Subsequently, it focuses on strategies to enhance the performance of gel-based evaporators, specifically addressing the achievement of photothermal stability, mechanical robustness, salt resistance, interfacial stability and antibiofouling stability through rational structural design and exploitation of intrinsic gel properties to realize optimal evaporation performance. Scalable applications of gel-based SIE, including water treatment, auxiliary power generation, atmospheric water harvesting, and metal extraction, are highlighted. Finally, conclusions and perspectives outline current challenges and future research directions for gel-based SIE at both theoretical and practical levels.