Vertical porous MoS2/hectorite double-layered aerogel as superior salt resistant and highly efficient solar steam generators

Solar desalination which can produce freshwater by using green and renewable solar energy is considered as a promising strategy to mitigate water scarcity. However, in practical application, the crystallization and accumulation of salt will cause adverse impact on the water transportation, vapor generation efficiency, and long-term sustainable use of evaporator. Herein, we proposed a vertical porous MoS2/hectorite bi-layered aerogel for efficient solar steam generation with superior salt redissolution performances, excellent light absorption and outstanding local thermal effect. The top MoS2 layer functioned as efficient solar absorbers with excellent light absorption and photo-thermal conversion performances. For the bottom layer, the vertical water transport path and natural strong hydrophilicity of hectorite aerogel ensure stable water supply to the evaporation layer and prevent the accumulation of salt at the evaporation interface. The results show that the constructed superhydrophilic MoS2/hectorite bilayer aerogel has excellent self-driven salt removal performance, and can achieve self-cleaning within 30 min under extreme conditions simulating salt crystallization. In addition, the aerogels exhibited a steam generation rate of 1.32 kg m−2 h−1 and an evaporation efficiency of 85.99% under a light intensity of only 1 kW m−2. The superior performances of MoS2/hectorite double-layer aerogel, such as low cost, simple preparation, high strength and good salt resistance, make it suitable as portable evaporator for efficient solar interface desalination.