A Novel Aerogel‐Based Solar Evaporator with Triple‐Layered Low‐Tortuosity Pore Structures for Ultra‐High Salt Resistance

Abstract

Solar‐driven interfacial evaporation is a potential strategy to address freshwater scarcity. However, simultaneously achieving high evaporation performance and effective salt resistance remains a significant challenge. Herein, a triple‐layered aerogel‐based solar evaporator with low‐tortuosity pore structures (Tri‐ASEL) is constructed. Benefiting from the unique pore structures of Tri‐ASEL, it not only exhibits excellent water transport capacity, which is significantly increased by 237.5% compared to that of the aerogel‐based solar evaporator with uniform pore structures, but also effectively reduces the downward heat transfer owing to the low thermal conductivity of the top layer. Meanwhile, compared with the aerogel‐based solar evaporator with triple‐layered pore structures (Tri‐ASE), Tri‐ASEL can reduce the resistance of ion diffusion and shorten the diffusion pathways through the low‐tortuosity pore structures. Because of the effective coordination of the contradiction among the water transport, ion diffusion, and thermal insulation, Tri‐ASEL achieves a high evaporation rate of 2.803 kg m−2 h−1 and exhibits a remarkable evaporation efficiency of 97.95% under 1 sun. More importantly, it demonstrates excellent salt resistance and can operate stably in ultra‐high salinity brine (25 wt%) for more than 8 h without salt crystallization. This study provides a new approach for optimizing the structure design of evaporators.