Bio‐Inspired Sandwich‐Structured All‐Day‐Round Solar Evaporator for Synergistic Clean Water and Electricity Generation

Abstract The integration of solar‐driven interfacial evaporation and electricity co‐generation is considered a promising approach to simultaneously alleviate freshwater scarcity and the energy crisis. However, affected by intermittent solar irradiation/uncontrollable weather, the overall performance of solar‐driven evaporation in the real world is greatly reduced. Herein, inspired by antifreeze proteins in beetles that survive in extreme climates, all‐weather solar‐driven interfacial evaporators with a sandwich structure are designed. The top and bottom layers composed of MnO 2 ‐modified cotton cloth are used for photothermal conversion and water transport, meanwhile, the middle layer made of a phase change microcapsule/hydrogel composite serves for heat storage and release. Under 1 kW m −2 irradiation, the evaporator exhibits a high evaporation rate of 2.67 kg m −2 h −1 and an efficiency of 89.5%. In the dark, the heat released from the phase change layer supports an evaporation rate of 0.43 kg m −2 h −1 , 3.6 times that of pure water. Additionally, assembled with a thermoelectric module, the hybrid device achieves a stable output electricity power of 0.42 W m −2 under 1‐sun illumination and a prolonged output for 30 min in the dark. This work provides a novel approach for full‐time solar‐powered steam‐electricity co‐generation and a proof of concept for biomimetic steam generation/heat management integration.