Economical Salt-Resistant Superhydrophobic Photothermal Membrane For Highly Efficient And Stable Solar Desalination

Recently, solar-driven interfacial water evaporation has shown great potential in desalination. In a practical application, the inevitable pollution and accumulation of salt that make the evaporation efficient cannot be maintained for a long time. Herein, we report a flexible and economical superhydrophobic photo-thermal membrane composed of polyvinylpyrrolidone (PVP) and carbon nanotubes (CNTs) with a 1H,1H,2H,2H-perfluorodecyl-triethoxysilane modification, with a piece of expanded polystyrene used for support and thermal insulation. The prepared floating evaporation device showed a high energy efficiency of 91.1% and an evaporation rate of 1.41 kg m(-2)h(-1) under one solar irradiation, and neither salt accumulation nor a significant decrease in the evaporation rate of the device was observed after continuous operation for either 40 h or 18 evaporation cycles. In addition, the self-cleaning performance of the membrane enabled its surface to maintain high absorbance for a long time. With the stable and efficient evaporation performance of this device, it provided guidance for the application of efficient and long-term stable solar desalination.