Multishelled CuO/Cu₂O induced fast photo-vapour generation for drinking water

Solar thermal interfacial water evaporation is proposed as a promising route to address freshwater scarcity, which can reduce energy consumption and have unlimited application scenarios. The large semiconductor family with controllable bandgap and good chemo-physical stability are considered as good candidates for photo-evaporation. However, the evaporation rate is not satisfactory because the rational control of nano/micro structure and composition is still in its infancy stage. Herein, by systemically analyzing the photo-thermal evaporation processes, we applied the hollow multishelled structure (HoMS) into this application. Benefiting from the multishelled and hierarchical porous structure, the light absorption, thermal regulation, and water transport are simultaneously optimized, resulting in a water evaporation rate of 3.2 kg·m⁻²·h⁻¹, which is among the best performance in solar-vapour generation. The collected water from different water resources meets the World Health Organization standard for drinkable water. Interestingly, by using the CuO/Cu₂O system, reactive oxygen species were generated for water disinfection, showing a new route for efficient solar-vapour generation and a green way to obtain safe drinking water.