Mass production of biodegradable porous foam for simultaneous solar evaporation and thermoelectricity generation

To solve the global energy and freshwater crises, interfacial solar evaporation has received more and more attention. However, constructing 3D evaporators in a facile and cost-effective way is still a crucial challenge. In this work, we propose a cost-effective approach to construct 3D biodegradable foams by combining melt blending and surface coating for simultaneous solar-vapor and thermoelectricity conversion. Benefiting from the fast water supply and super-photothermal conversion, the foam attains an evaporation rate of 4.33 kg m-2 h-1 and electric power density of 0.8 W m-2 under 1 sun irradiation. In outdoor environments, the electricity produced by eight devices can power a small fan or a LED display. Moreover, the foam can be degraded in 2% NaOH solution after use. The proposed method presents a promising approach for the mass production of 3D evaporators to solve freshwater and electricity shortages in off-grid or remote areas. We propose a cost-effective approach to construct 3D biodegradable foams by combining melt blending and surface coating, which show high performance in simultaneous solar-vapor conversion and thermoelectricity generation.