In situ generation of carbonized polyaniline nanowires on thermally-treated and electrochemically-etched carbon fiber cloth for high efficient solar seawater desalination

Utilizing solar energy to evaporate water is an environment-friendly and promising approach for various applications such as seawater desalination. Various photothermal materials can be developed for evaporating water, however, there are still some drawbacks such as complicated synthesis processes, weak/narrow absorbance, bulkiness, and low evaporation rate, which severely limit their commercial applications. Herein, we reported the preparation of electrochemically-etched carbon fiber cloth with surface-coated carbonized polyaniline nanowires (ECFC/CPANW) based on thermally-treated pre-oxidized polyacrylonitrile fiber cloth for highly efficient solar steam generation. This ECFC/CPANW composite has the advantages of low thermal conductivity, effective broadband solar absorption, good hydrophilicity and water transfer ability. When ECFC/CPANW and polyurethane foam are bound together as a solar evaporator, ECFC/CPANW achieved the highest vaporization efficiency of up to 93.7% under 1 sun illumination, which is more efficient than those of most materials previously reported. Therefore, this kind of photo-thermal conversion material with low cost, good stability and environmental friendliness could envision promising practical application for water treatment. Electrochemically etched carbon fiber cloth with surface-coated carbonized polyaniline nanowires (ECFC/CPANW) shows three-dimensional porous structure, low thermal conductivity, high mechanical strength, broadband solar absorption and efficient water supply capacity, resulting in highly efficient solar steam generation performance. [Display omitted] •The ECFC/CPANW is designed for solar seawater desalination.•The ECFC/CPANW shows evaporation rates of 1.4255 kg m-2 h-1 under 1 kW m-2 with the evaporation efficiency up to 93.7%.•The ECFC/CPANW exhibits good desalination performance with the ion rejection over 99.9%.