Janus membrane with enhanced interfacial activation for solar evaporation

Low solar spectrum coverage, high evaporation enthalpy, and undesired salt deposition severely limited the solar-driven interfacial evaporation technology for further sewage purification and seawater desalination. To overcome these problems, we designed an amphiphilic Janus-structured polyaniline (PANI)/ZrC/cellulose acetate (CA) (J-PZCA) membrane. Firstly, the interfacial interaction between PANI and ZrC enhances the photoabsorption and photothermal conversion efficiency. Secondly, low thermal conductivity reduces the heat lost at the interface. Most importantly, ZrC could facilitate interfacial activation, which weakens the intermolecular forces of water by affecting the hydrogen bond. Under 1 solar irradiation (1 sun), the composite membrane exhibits a high evaporation rate of 1.31 kg m⁻² h⁻¹ and an excellent efficiency of 79.4%. In addition, the sewage purification and seawater desalination experiments reveal a remarkable purification capability of J-PZCA membrane. Especially for the treatment of high-concentration salt solution, it realizes a long-term stable evaporation performance due to the excellent salt deposition resistance. Therefore, the J-PZCA membrane constructed in this study provides a new perspective for the design of efficient interfacial evaporation devices.