Cu-Fe3O4/sodium alginate/polyacrylamide hydrogel evaporator for solar seawater desalination

As an environmentally friendly seawater desalination method, solar interface evaporation is considered to be a promising solution to ease the freshwater shortage. In this paper, porous Cu-Fe3O4/sodium alginate/polyacrylamide hydrogel was prepared by double chemical crosslinking method using sodium alginate, polyacrylamide and Cu-Fe3O4 nanoparticles with good SPR effect as raw materials. The effects of Cu-Fe3O4 nanoparticle concentration, light intensity and salt water concentration on the evaporation performance of hydrogel evaporator were studied. It was found that under the light intensity of 1 sun, the evaporation efficiency and thermal efficiency of 3.5 wt% seawater in the hydrogel evaporator containing Cu-Fe3O4 nanoparticles with a concentration of 0.26 % can reach 64.7 % and 95.24 %, respectively. In addition, the Cu-Fe3O4/sodium alginate/polyacrylamide hydrogel evaporator has good reusability and salt self-cleaning ability. The seawater desalination experiment in real environment shows that the hydrogel evaporator with low cost benefit has broad application prospects in the field of seawater desalination.