At present, human beings are widely plagued by the lack of fresh water resources. Although solar-driven seawater desalination technology has developed relatively rapidly, reports on seawater desalination often pay too much attention to increasing the rate of seawater desalination, while ignoring the concentration and crystallization of salt at the evaporation interface during the desalination process. The salt accumulated at the evaporation interface severely destroys its high solar energy absorption characteristics, which is a huge challenge for continuous and efficient solar desalination. Based on the previous work of the research group and inspired by the physiological functions of reed leaves, Deng Hongbing and others further designed nanofiber aerogels (R-NFAs) with parallel arrangement of pipes and hydrophobic surfaces to achieve salt-tolerant solar seawater desalination.

In the solar seawater desalination experiment, although the evaporation rate of B-NFAs with non-biomimetic structure rose sharply in the first few minutes and was significantly higher than that of R-NFAs with bionic structure, the evaporation rate began to decrease after 10 minutes, and the evaporation rate began to decrease after 15 minutes. After that, its evaporation rate is already lower than that of R-NFAs. The surface of B-NFAs is completely covered by salt crystals, which significantly reduces their light absorption properties, making it difficult to maintain long-term effective evaporation. For R-NFAs, although salt crystals appear on the side of the evaporator, the top surface and bottom hydrophilic layer remain in their original state, so the evaporator still maintains an efficient evaporation rate.

(a) Light absorption, water transmission, steam generation and salt crystallization of traditional solar evaporators, (b) Microstructure and hydrophobicity of reed leaves, (c) Reed leaf-inspired nanofiber aerogel (R-NFAs) evaporation The light absorption, water transmission, steam generation and salt resistance of the filter, (d) the evaporation rate of R-NFA and B-NFAs in salt water, (e,f) the salt resistance of R-NFA and the salt of B-NFA accumulation

The research was funded by the National Natural Science Foundation of China, the Hubei Provincial Key R&D Project, and the Hubei Provincial Outstanding Youth Fund.