Multifunctional Cotton With PANI-Ag NPs Heterojunction And Its Solar-driven Water Evaporation Application

Due to an increase in population density,human quality of life requirements,and the pollution of water sources,the lack of freshwater resources poses a great challenge to the survival of mankind and sustainable societal development.Although there are many methods to produce freshwater from seawater by desalination,such as reverse osmosis and electrodialysis,these technologies require well-developed infrastructure,centralized installations,and high energy consumption,which make them unsuitable for use in remote developing regions without conventional power grids.Especially for polluted seawater treatment,contamination is also a challenge faced by membrane filtration.Therefore,people have conducted research on solar distillation because it has a simple structure and is not harmful to the environment.This technology has been used as a sustainable freshwater production strategy applied in developing regions,but there are oil and organic pollutants in the original water source,which seriously reduces Improve the evaporation performance and cause environmental hazards.In this paper,biochemical cotton（BC）was used as the substrate,polydopamine（PDA）functional coating was used to adhere carboxylated multi-walled carbon nanotubes（MWCNTs-COOH）and reduce Ag NPs,and finally hydrochloric acid-doped polyaniline（PANI）was grown in situ.Multifunctional cotton was successfully prepared.Under one sunlight(1 k W m^-2),the water evaporation rate of the multifunctional cotton reached 1.37 kg m^-2 h^-1,and the photothermal conversion efficiency was 84.7%.The water evaporation rate can reach 1.35 kg m^-2 h^-1 and 1.33 kg m^-2 h^-1 even in simulated seawater and organic wastewater,respectively,and it also has excellent salt resistance.The modified biochemical cotton can also reach an average evaporation rate of 0.62 kg m^-2 h^-1 when placed outdoors.Notably,various organic pollutants in the water source were completely removed by separation,visible-light catalytic degradation or adsorption with efficiencies of 99.5%,99.3%,and 97.0%,respectively.Considering these advantages,the prepared multifunctional cotton is an outstanding candidate for water evaporation from various sources.