An Antimicrobial, Environmental Protection, and High‐Efficiency Solar Steam Generator Based on Carbonized Sawdust

Solar‐powered desalination technology offers a promising solution to the global scarcity of freshwater resources. Recently, researchers have become interested in solar‐powered steam generators utilizing biomass materials. Herein, wood waste (sawdust) is recycled and subjected to high‐temperature treatment to obtain carbonized sawdust (CSd), which is sprayed onto the surface of a sponge to assemble a sponge‐based light absorber. The impact of sawdust carbonization temperature on water evaporation performance is examined, and it is found that a sponge‐based light absorber with a sawdust carbonization temperature of 600 °C exhibits a photothermal conversion efficiency of 87.7% while maintaining low‐energy consumption. Incorporating metal Ag into the light absorber improves water evaporation performance (photothermal conversion efficiency of 92.3%) and provides antibacterial properties. This photothermal evaporator maintains 89% photothermal conversion efficiency after 24 h of operation under 1 sun irradiation in 3.5 wt% NaCl solution. The antibacterial, efficient solar steam generator is expected for practical seawater desalination.