Hydrogel fiber fabric combining rapid water transport, thermal localization, and large-scale production for ultra-high salt-resistant solar desalination

Abstract

Solar vapor generation (SVG) is one of the most promising strategies for addressing the freshwater shortage crisis. However, fewer existing solar evaporators combine excellent evaporation rates, salt resistance, and large-scale production potential, which are the keys to realizing industrialization. Herein, we prepare sodium alginate/reduced graphene oxide (SA/rGO) hydrogel fibers with complex nano-network structures and introduce a novel compact hydrogel fiber fabric (HFF-C) evaporator by integrating the advantages of hydrogel and fabric for the first time. The HFF-C evaporator exhibits a synergistic impact based on its porous structure and capillary effect between the fibers, along with efficient thermal management, resulting in both efficient water transport and thermal localization. The constructed HFF-C evaporator demonstrates an exceptional evaporation rate (4.13 kg m−2 h−1) in 20 wt% brine under one sun illumination, which is the highest reported value to our knowledge. Importantly, no salt deposition occurs on the evaporator’s surface over 8 h of operation. Furthermore, we successfully prepare an HFF-C evaporator with a large size of 13 × 100 cm2 using a multibeam loom. This study presents a novel design concept for a solar hydrogel-based evaporator with excellent evaporation rates, ultra-high salt resistance, and large-scale production potential, thus promising significant advancements in the practical application of SVG.