Mechanically durable, sustained corrosion-resistant photothermal nanofiber membrane for highly efficient solar distillation
So far, solar distillation based on photothermal membranes is attracting ever-increasing attention in the less developed regions for water purification. Well, the raw water resources for solar evaporation was generally beyond the natural hydrology water cycle and contained highly salinity and corrosion. In this process, a core-shell structured PDA/PEI/PPy@PI nanofibrous membrane (NFM), comprising robust PI nanofibrous substrates, PPy photothermal layer and anticorrosion PDA/PEI layer, were developed as a photothermal membrane, which exhibited broadband solar absorption (93.0%) and sustained anti-corrosion capacity for 30 days. Besides, the core-shell structure can effectively prevent the swelling of the membrane and maintain excellent mechanical strength even at wet state. The evaporation system based on PDA/PEI/PPy@PI NFM achieved a high solar evaporation rate of ≈ 1.43 kg m-2 h-1, corresponding to a light-to-vapor efficiency of ≈ 86.9% under the illumination of 1-sun. Due to its sustained corrosion-resistant, mechanically durable at wet state and highly solar evaporation capacity, this NFM is expected to have great potential for the long-term solar distillation application.