Dual-Layer Multichannel Hydrogel Evaporator with High Salt Resistance and a Hemispherical Structure toward Water Desalination and Purification

: Interfacial solar steam generation technology has been considered as one of the most promising methods for seawater desalination. However, in practical applications, salt precipitation on the evaporation surface reduces the evaporation rate and impairs long-term stability. Herein, a dual-layer hydrogel-based evaporator that contains a microchannel-structured water-supplying layer and a nanoporous lightabsorbing layer was synthesized via sol-gel transition and hot-ice template methods. Contributed by the designed structure-induced accelerated salt ion exchange, the hemispherical dual-layer hydrogel evaporator showed excellent salt formation resistance property, as well as a high evaporation rate reaching 2.03 kg m-2 h-1 even under high brine concentration conditions. Furthermore, the hydrogel-based evaporator also demonstrated excellent ion rejection, high/low pH tolerance, and excellent purification properties toward heavy metals and organic dyes. It is believed that this type of dual-layer multichannel evaporator is promising to be used in seawater desalination, water pollution treatment, and other environmental remediation-related applications.

Automated summary

This study developed a dual-layer hydrogel-based evaporator with excellent resistance to salt formation, high evaporation rate, and purification properties. It has potential applications in seawater desalination, water pollution treatment, and other environmental remediation-related fields.