Synergistic Effect of Photothermal Conversion in MXene/Au@Cu2−xS Hybrids for Efficient Solar Water Evaporation

Abstract A three‐plasmon hybrid, in which core–shell Au@Cu 2−x S hybrids are bonded with ultrathin Ti 3 C 2 T x MXene, is prepared for high‐efficiency photothermal conversion and membrane‐based solar water evaporation for the first time. The MXene/Au nanorod@Cu 2−x S hybrids display excellent photothermal conversion efficiency under irradiation of an 808 laser, causing by the three‐plasmon‐induced synergistic plasmonic absorption and heating effects as well as the multichannel charge transfer between the components. Then, Au nanosphere@Cu 2−x S and Au nanorod@Cu 2−x S hybrids are mixed and combined with MXene to serve as the membrane material, which shows excellent light absorption ranging from ultraviolet to near‐infrared region. By transferring the membrane materials on a hydrophilic cotton piece, the as‐prepared photothermal membrane displays a high evaporation rate of 2.023 kg m −2 h −1 and light‐to‐heat conversion efficiency of 96.1% under 1‐sun irradiation due to the synergistic photothermal conversion and over 96% of solar light absorption efficiency. Furthermore, a home‐made solar evaporation device enabling automatic inflow of untreated water and outflow of evaporated water is designed based on the principles of liquid pressure and connectors. The seawater desalination and sewage treatment experiments performed on the device and membrane indicate the great potential in solar‐light‐driven water purification and drinkable water generation.