Bioinspired structural and functional designs towards interfacial solar steam generation for clean water production

Fresh water shortage is rapidly emerging as a global crisis, threatening the future development of human society. Extracting fresh water from seawater, wastewater and even atmospheric water efficiently has become a critical challenge to the research community. In recent years, solar-driven evaporation has aroused enormous research interest owing to its low-cost and sustainable potential. As a new bioinspired approach for clean water production, interfacial solar steam generation makes direct use of solar energy to generate water steam through latent heat. Fresh water can then be collected by condensing the water steam on a colder substrate. To date, quite a number of photothermal materials and rational structure designs for efficient solar evaporators have been reported. In this review, the design principles and evaporation systems for interfacial solar evaporation are summarized. Multifunctional designs of evaporators, salt-rejection, and antifouling capability are also discussed, which is of great significance to long-term and efficient solar water collection. In the last section, some prospects for the development of solar evaporators are proposed.