Fabrication of a Highly Efficient Wood-Based Solar Interfacial Evaporator with Self-Desalting and Sterilization Performance

Solar interfacial evaporation based on wood-derived materials has been considered a promising strategy for desalination and wastewater purification. Herein, we adopted delignified wood (DW) as the water transport substrate and lignosulfonate (LS)-modified narrow-band gap semiconductor nickel disulfide (NiS2) as the light-absorbing agent (LS-NiS2) to fabricate a high-efficiency evaporator (LS-NiS2@ DW). On the one hand, the high absorbance (>95%) within a broad wavelength range and excellent photothermal conversion efficiency of LS-NiS2 endow efficient solar energy utilization. On the other hand, the hydrophilicity of DW facilitates water activation, which results in a lower evaporation enthalpy of LS-NiS2@DW (1274.4 kJ kg-1) than that of pure water. By combining LS-NiS2 and DW, LS-NiS2@DW achieved an evaporation rate as high as 2.80 kg m-2 h-1 under one sun irradiation (1 kW m-2), and the evaporation efficiency reached 87.4%. Notably, LS-NiS2@DW exhibits a high evaporation rate (2.42-2.69 kg m-2 h-1) in simulated seawater for 24 h with no salt crystals formed on the surface. Moreover, LS-NiS2@DW shows high antibacterial activity with about 90% reduction in bacterial survival rate. This work could provide new perspectives for the design of a high-efficiency wood-based photothermal evaporator.