Self-polymerized hydrogel for efficient solar-driven desalination, antibacterial properties and water purification

The traditional hydrogel evaporators used for interfacial solar vapor generation (SVG) are considered one of the most appealing desalination technologies to global freshwater crisis. In this paper, a simple method like dough making is designed to prepare a self-polymerizing porous hydrogel (PDIH) evaporator. Not only can its morphology be changed arbitrarily, but also the pore size of the hydrogel evaporator can be controlled only by changing the concentration of saline water. The hydrogel evaporator was used in high concentration saltwater, an excellent evaporation rate of 3.1 kg m −2  h −1 and >90 % energy efficiency were obtained under simulated solar irradiation (1.0 kW m −2 ) at 10 % brine, and similar evaporation rates were obtained in seawater and 7 % brine. Additionally, the hydrogel exhibited excellent antibacterial properties and had a high capacity of sewage disposal (organic dyes and heavy metal solutions). It is expected that the preparation of this hydrogel evaporator will promote the development of SVG technology in high concentration saline.