Rational design of different interfacial evaporators for solar steam generation: Recent development, fabrication, challenges and applications

In recent years, interfacial solar steam generation (ISSG) has been considered a potential solution to the current energy crisis and lack of freshwater. In ISSG, a novel solar interfacial evaporator is allowed to float on the bulk water. It has the ability to supply adequate water to the evaporative surface, suppress heat loss and improve light-to-vapour conversion efficiency. Since 2014, innovative photothermal materials as well as different types of advanced structural designed interfacial evaporators have been introduced in ISSG. This rapid development of evaporators has resulted in the evaporation efficiency of 100 % with least energy consumption. In this review, ultrahigh evaporation performance of ISSG with different types of solar evaporators (foam, wood, hydrogel, aerogel, membrane, 3D printing, paper and plant-based evaporators), fabrication process and vapour formation mechanisms are explored. After examining the latest technologies and advancements in research, potential methods to enhance the efficiency of ISSG under different levels of solar irradiation are described. Further, the challenges such as salt rejection technique, minimizing heat loss, water transport technique and condensation process are reviewed. Subsequently, the applications of ISSG in dye removal, water desalination, microorganism removal and power generation are explored. Eventually, the summary and outlook for improving this technology for real-world applications are summarized.