Superhydrophilic floral foam-based solar evaporator with excellent salt-resistance and cost advantages for high efficient desalination

Abstract

Effective management of heat, outstanding water transport paths, and hydrophilicity are essential for porous solar-driven interfacial evaporators, but their development still faces many difficulties. Here, by cross-linking a carbon black (CB)/polyvinyl alcohol (PVA) slurry with three-dimensional super hydrophilic floral foam (FF) to form a CB/PVA functional film on the surface of FF, a CB/PVA-decorated floral foam based (FFCP) solar-driven water evaporator with low-cost was finally obtained. Owing to the super hydrophilicity, sufficient water supply, self-holding water capacity and the special porous structure of the FF, as well as efficient light absorption and photothermal conversion efficiency of the dispersed CB. The gas-liquid interface temperature of the optimized FFCP-1.0 evaporator reaches 41.2 °C under single solar irradiation, obtaining an evaporation rate of up to 1.69 kg m−2 h−1. In addition, the FFCP-1.0 evaporator had a great evaporation rate in highly concentrated salt solutions. Moreover, the FFCP-1.0 evaporator has remarkable purification effects on seawater, organic dye effluents and heavy metal ion solutions. The evaporator has low cost, excessive evaporation rate and excellent durability. Therefore, this work is of considerable scientific significance for promoting the practical application of porous-based solar evaporators and clean water production.