Biopolymer Hydrogel-Based Salt-Resistant Evaporator for Solar-Energy-Driven Desalination and Water Purification
Jingbo Zhu, Xuelong Chen, Caiyan Zhang, Baozheng Cui, Ningjing Bai, Wei Wang, Huixin Wang, Chenlong Kang, Youmao Tang, Zewen Li, Haijun Niu, Zhe Wang
Abstract
Interfacial solar steam generation (ISSG) has recently received much attention as a low-carbon-footprint and high-energy-efficient strategy for seawater desalination and wastewater treatment. However, achieving the goals of a high evaporation rate, ecofriendliness, and high tolerance to salt ions in brine remains a bottleneck. Herein, a novel hydrogel-based evaporator for effective solar desalination was synthesized on the basis of sodium alginate (SA) and carboxymethyl chitosan (CMCS) incorporating a carbon nanotube (CNT)-wrapped melamine sponge (MS) through a simple dipping–drying–cross-linking process. The hydrogel-based evaporator reaches a high evaporation rate of 2.18 kg m –2 h –1 in 3.5 wt % brine under 1 sun irradiation. Furthermore, it demonstrated excellent salt ion rejection in high-concentration salt water. Simultaneously, it exhibits excellent purification functionality toward heavy metals and organic dyes. This study provides a simple and efficient strategy for seawater desalination and wastewater treatment.