Synergy of copper Selenide/MXenes composite with enhanced solar-driven water evaporation and seawater desalination

Despite significant of solar energy to power water evaporation in seawater desalination, the commercial application of this technology is limited by the poor light absorption and low photothermal conversion of existing photothermal materials. Herein, we report a simple method for solar-driven water evaporation using a device comprising Cu2-xSe/Nb2CTx nanocomposites supported by a glass microfiber membrane, which utilizes cotton thread as water transport pathway. The proposed device demonstrates excellent light absorption, water transportation, and thermal management. Benefiting from the strong synergetic photothermal effect of Cu2-xSe and Nb2CTx, the Cu2-xSe/Nb2CTx nanocomposites function as an efficient solar absorber with excellent photothermal conversion efficiency. The rough surface, low thermal conductivity and good hydrophilicity of glass microfiber membrane could maximize light capture, limit heat loss, and timely replenish water during the water evaporation process. When evaluated as a water evaporation system for outdoor seawater desalination, the system achieved a water evaporation of 12.60 kg·m-2 within 6 h. High fresh water generation rate is an important embodiment of high photothermal conversion efficiency. This study demonstrates a new route for designing solar desalination devices with high photothermal conversion properties.