Three-dimensional hierarchical Cu_xS-based evaporator for high-efficiency multifunctional solar distillation

Solar distillation is a promising and sustainable technique for extracting clean water from seawater and/or wastewater. However, the fabrication of evaporators that can simultaneously exhibit high-efficiency, antifouling, and antibacterial properties remains a great challenge. Herein, we for the first time report the Cu_xS-based solar water evaporator by assembling and designing the dual-phase Cu_xS composite nanorods into three-dimensional (3D) hierarchical architecture foam with efficient light trapping, superhydrophilic and underwater superoleophobic properties. Owing to the enhanced synergistic photothermal conversion and the confined two-dimensional (2D) water path, the fabricated Cu_xS/Cu foam (SCF) evaporator can achieve extremely high water evaporation rate of 1.96 kg m⁻² h⁻¹ with energy efficiency of 94.5%, which is among the highest performance for inorganic semiconductor-based evaporators. The developed device can also maintain a high evaporation rate of 1.73 kg m⁻² h⁻¹, and an average rate of 5.2 L m⁻² day⁻¹ in a 30-day consecutive outdoor test, for producing clean water from oil-in-water emulsion with excellent antifouling, antibacterial, and ion rejection properties. As a proof-of-concept application, the Cu_xS-based evaporator is demonstrated to have superior capability for multiphase purification of clean water and organic solvent from dyed solutions.