A Bilayered Wood-Poly(3,4-ethylenedioxythiophene):Polystyrene Sulfonate Hydrogel Interfacial Evaporator for Sustainable Solar-Driven Sewage Purification and Desalination

Solar-driven interfacial evaporation and purification is a promising solar energy conversion technology to produce clean water or solve water scarcity. Although wood-based photothermal materials have attracted particular interest in solar water purification and desalination due to their rapid water supply and great heat localization, challenges exist given their complicated processing methods and relatively poor stability. Herein, we propose a facile approach for fabricating a bilayered wood-poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (wood-PEDOT:PSS) hydrogel interfacial evaporator by direct drop-casting and dry-annealing. Benefiting from the unique combined merits of the wood-PEDOT:PSS hydrogel evaporator, i.e., excellent light absorption (~99.9%) and efficient photothermal conversion of nanofibrous PEDOT:PSS and the strong hydrophilicity and fast water transport from wood, the as-fabricated bilayered wood-PEDOT:PSS hydrogel evaporator demonstrates a remarkably high evaporation rate (~1.47 kg m−2 h−1) and high energy efficiency (~75.76%) at 1 kW m−2. We further demonstrate the practical applications of such an evaporator for sewage purification and desalination, showing outstanding performance stability and partial salt barrier capability against a continuous 10-day test in simulated seawater and an ultrahigh ion removal rate of 99.9% for metal ion-containing sewage. The design and fabrication of such novel, efficient wood-based interfacial evaporators pave the way for large-scale applications in solar water purification.