Three-dimensional porous photo-thermal fiber felt with salt-resistant property for high efficient solar distillation

Abstract The urgent need for fresh water resource is a public issue facing the world. Solar distillation for seawater desalination is a promising freshwater production method. Interfacial solar evaporation systems based on 2D photo-thermal membranes have been widely studied, but salt pollution is one of the main challenges for solar distillation. In order to solve this problem, a hydrophilic three-dimensional (3D) porous photo-thermal fiber felt (PFF) was obtained by one-step method, through a simple polydopamine (PDA) coating method with hydrophobic graphite felt as a substrate. The PFF had a good evaporation rate of 1.48 kg m−2 h-1 and its corresponding light-vapor conversion efficiency reached 87.4 %. In addition, the PFF exhibited an excellent salt-resistant ability when applied to photo-thermal evaporation of high-salinity seawater with 10 wt% NaCl, owing to its intrinsic 3D macroporous structure for the migration circulation of salt ions. The development of the PFF offers a new route for the exploration of salt-resistant photo-thermal materials and is promising for the practical application of solar distillation.