Biomass Waste-Derived Solar Evaporator for Efficient and Low-Cost Water Evaporation

Solar-driven interfacial water evaporation is a green and energy-saving water treatment technology, yet key issues remain the low efficiency, high cost, and complicated fabrication of solar evaporators. With a unique natural structure, good environmental friendliness, and low cost, biomass-based materials have attracted extensive research interest as solar absorbers. Herein, banana peel, one of the most common biomass wastes, is adopted as raw material for solar water evaporation and subjected to a carbonization process. The carbonized banana peel (CBP) presents a dark rough surface and a hierarchically inner porous structure, resulting in good solar absorption and water transfer ability. Consequently, a high water evaporation rate of 1.35 kg m(-2) h(-1) and corresponding solar-to-vapor conversion efficiency of 87.5% are achieved under 1 sun irradiation. Furthermore, the CBP also exhibits outstanding performance in seawater desalination and wastewater purification. This work demonstrates a sustainable strategy for low-cost and efficient solar-driven water purification.