A salt-resistant and antibacterial Cu2ZnSnS4-based hydrogel for high efficiently photothermal distillation in seawater desalination and sewage purification.

Solar steam generation technology (SSGT) by using unlimited solar energy is regarded as one of the most promising sustainable technologies to produce clean water. However, most of researches about SSGT simply focused on how to improve salt resistance as well as exclude inorganic and organic pollutants in targeted water, and only very limited researches pay attention to the micro-organisms in the collected water. Herein, one porous Cu2ZnSnS4-based photothermal hydrogel (CZTS-PH) with antibacterial property as well as good salt resistance was successfully prepared. The CZTS-PH was measured with the water evaporation rate as high as 3.249 kg m-2 h-1 and photothermal conversion efficiency of 96.3% under one sun irradiation. Impressively, owing to the amino groups in the skeleton, CZTS-PH can significantly deteriorate the cell membrane and lead to the death of the Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), which ensures its long-term stability photothermal conversion and the safety of clean water. Overall, the admired photothermal conversion efficiency, the excellent salt resistance and antibacterial performance suggest that CZTS-PH could be a promising full-scaled device applied in seawater desalination and water purification.