One-step preparation of a hydrogel evaporator by in-liquid pulsed discharge for efficient solar desalination

Abstract

The usage of solar energy to achieve seawater desalination is emerging as an alternative to solve the problem of energy and fresh water shortage. In this work, a photothermal hydrogel is prepared by direct in-liquid pulsed discharge plasma, by which the cross-linking of the hydrogel was promoted rapidly by self-initiated active substances (such as ·OH, ·O, etc.). The prepared photothermal hydrogel has great evaporation performance and the evaporation rate in water can reach 1.316 kg m⁻² h⁻¹ and an energy utilization efficiency of up to 89.57%. Besides, the prepared photothermal hydrogel exhibits stable evaporation characteristics under extreme conditions, and has high interception of salts, heavy metals, dyes and oils. The results show that the photothermal hydrogel prepared by in-liquid pulsed discharge plasma has broad application prospects in seawater desalination.