Thermal insulation design for efficient and scalable solar water interfacial evaporation and purification

In recent years, solar desalination and water evaporation/purification with various artificial architectures have drawn significant attention. Herein, we introduce a rational design structure for efficient solar water evaporation and purification, focusing on the balance between water transportation and thermal insulation.Natural wood after a simple flame treatment on the surface was utilized as the solar absorber, with a high solar absorbance(～90 %), good hydrophilicity, and excellent heat localization abilities. Besides,a thermal insulator(polystyrene foam) was used to further reduce the thermal loss, and the optimized ratio between the water path and thermal insulator was obtained. A set of floating foam-flamed-wood(F-F-wood) devices were fabricated with a high evaporation rate of 3.92 kgmh, exhibiting photothermal purification abilities from seawater and wastewater containing organic dyes and heavy metals. This study sheds light on the rational design of scalable and low-cost devices for solar water evaporation and purification.