Wood-Based Solar Interface Evaporation Device with Self-Desalting and High Antibacterial Activity for Efficient Solar Steam Generation

The main challenges of a solar steam generation device based on biomass materials are complicated processing techniques and relatively low efficiency. To solve these problems, we reported a simple immersion treatment method by depositing polydopamine (PDA) and silver nanoparticles (AgNPs) on natural wood to prepare a novel solar interface evaporation device. Ag-PDA@wood exhibits a unique bilayer structure. The absorbance of the top light absorption layer is higher than 96% in a wide wavelength range (300-2500 nm). Owing to the synergistic photothermal effect between PDA and AgNPs, Ag-PDA@wood has ultrafast solar-thermal response (a temperature increase of 42.5 degrees C within 5 min under 1 sun), and more heat is located at the steam generation interface (the surface temperature is 45.1 degrees C). The natural wood layer at the bottom with low thermal conductivity provides sufficient water supply and reduces the bulk heat loss. A high evaporation rate of 1.58 kg m(-2) h(-1) is achieved using Ag-PDA@wood under 1 sun (1 kW m(-2)). Its evaporation efficiency reaches 88.6%. The results upon sewage treatment and seawater desalination indicate that Ag-PDA@wood has an excellent purification ability and self-desalting capacity. More importantly, when compared to traditional solar evaporators, Ag-PDA@wood exhibits high antibacterial activity. The result of this antibacterial experiment shows that this material almost completely kills harmful bacteria. Therefore, Ag-PDA@wood has a high application potential in seawater desalination and sewage purification, providing a significant incentive to solve the problem of insufficient freshwater supply.