Welding Pollen-Based Solar Evaporator for Clean Water Production

The world faces a trade-off between water availability and food supply, as agricultural irrigation consumes the largest freshwater globally. Inspired by inherent water transport channels in plants, a cost-effective welding pollen-based solar evaporator (PSE) is developed to obtain clean water from seawater desalination. Based on the convex and folded surface structure of natural pollen (Helianthus annuus) and the porous structure of welding pollen evaporator interconnection, the PSE reveals an efficient evaporation rate of 1.86 kg m^-2 h^-1 under one-sun illumination and further exhibits excellent cycling performance for 10 cycles tested in 7.0 wt.% saline water without salt accumulation. In addition, PSE has superior mechanical stability (3.44 MPa) and remains stable after being immersed in pH 1 and 14 solutions for 24 h without sacrificing mechanical properties. Importantly, the work has demonstrated the success of the freshwater collected from the evaporation process, which can effectively facilitate the cultivation of lettuce, rice, and wheat. These findings highlight the practical application of pollen as a low-cost, eco-friendly natural resource in interfacial solar evaporation. Furthermore, they inspire addressing current global water scarcity and promoting sustainable agriculture.