Interconnected Porous Fabric-Based Scalable Evaporator with Asymmetric Wetting Properties for High-Yield and Salt-Rejecting Solar Brine Treatment

Solar-driven interfacial evaporation has been considered as a promising approach for treating high-salinity brine, which mitigates ecological pollution as well as produces fresh water. Despite the extensive research efforts, challenges remain regarding the stably high-yield solar treatment of high-salinity water on a large scale. Here, we demonstrate an interconnected porous fabric-based scalable evaporator with asymmetric wetting properties fabricated by weaving technique for high-efficiency and salt-rejecting solar high-salinity brine treatment. Three-dimensional interconnected micropores ensure effective convection-induced fast vapor diffusion, leading to a high evaporation rate in the natural environment with the convective flow. The Janus structure effectively separates absorption and evaporation surfaces for stable salt resistance even under fast evaporation. It is observed that the evaporator achieves a high evaporation rate of 2.48 kg m⁻² h⁻¹ under 1-sun illumination and airflow of 3 m s⁻¹ when treating 15 wt% saline. Notably, the outdoor experiment demonstrates that there is neither salt precipitation on the surface nor a decrement in evaporation rate during the 5-day evaporation until water and solute have completely been separated. The interconnected porous fabric with asymmetric wetting properties can be easily and massively produced by industrialized weaving techniques, showing great potential for scalable and efficient solar water treatment of high-salinity brine and industrial wastewater.

Graphical Abstract