Synthesis of layered Co9S8-based composites for high-efficiency rotating evaporation of saturated brine

Harvesting freshwater via solar interfacial evaporation is a promising strategy with net-zero emissions. To achieve long-term stable freshwater acquisition, researchers have developed dynamic solar-driven water evaporators. However, these evaporators exhibit limited evaporation rates due to the insufficient photothermal conversion properties of the materials used. In this study, we prepared Co₉S₈/CoNiO₂/Au composite materials through in-situ topological transformation, thereby improving the effect of the heterogeneous crystal lattice mismatch on electron transport. By embedding these materials into a spherical polyurethane sponge, we developed a new type of self-rotating evaporator with a solar full-spectrum absorbance of 95.84 %. The evaporator stably exhibited an evaporation rate of 3.10 kg m⁻² h⁻¹ within 240 h in saturated brine. The present work provides insights into the preparation of photothermal composites and the development of high-efficiency stable solar evaporators.