Guixin Hu, Huajian Liu, Kuankuan Liu, Huiyue Wang, Xueying Wen, Lijie Liu, Yan She, Lingling Feng, Ran Niu*, Jiang Gong*

All-in-one carbon foam evaporators for efficient co-generation of freshwater and electricity

Advanced Functional Materials (2025) Accept. (IF2024 = 18.5)

Combining interfacial solar steam evaporation with power generation to produce freshwater and electricity is an effective approach to alleviating freshwater scarcity and energy crises. However, constructing low-cost, efficient integrated evaporator-generator devices remains challenging, and the synergistic mechanism underlying evaporation-power co-generation is not yet well understood. Herein, we design low-cost carbon foam-based bifunctional evaporators that effectively achieve freshwater and electricity co-generation. Carbon foam is obtained from waste polyester using a ball-milling-assisted carbonization strategy. The bifunctional evaporator demonstrates excellent water transport, outstanding sunlight absorption, and low evaporation enthalpy. It achieves an ultra-high evaporation rate of 3.03 kg m^-2 h^-1 with the conversion efficiency of 99.4%. Additionally, it exhibits continuous high voltage (0.33 V) and current output (14.4 μA), surpassing the performance of state-of-the-art carbon materials-based evaporators/generators. The outcome of molecular dynamics simulations demonstrates that the stronger interaction of surface functional groups in carbon foam with Na⁺ than Cl^- results in the formation of flow potential, when exposed to sunlight, further insights into the synergistic mechanism of power generation. This study expands a new path for sustainable electricity and freshwater co-production by collecting natural energy using single, low-cost, carbon foam-based functional evaporator devices.