Polyethylene glycol assisted solvothermal synthesis of ZnIn2S4 with zinc vacancy and enhanced internal electric field for photocatalytic CO2 reduction

In this work, polyethylene glycol is adopted as the solvent for the synthesis of ZnIn2S4 photocatalyst by the solvothermal method. Compared with the pristine ZnIn2S4 synthesized in H2O solvent, those ones prepared in the polyethylene glycol solvent possess several unique features that are beneficial for photocatalytic CO2 reduction, such as the increased Zinc vacancy level, the enlarged band gap, and the enhanced built-in internal electric field. These features allow for better charge separation efficiency, thereby improving the photocatalytic activity. The optimized ZnIn2S4 can achieve a CO yield rate of 20.14 μmol/g/h at the gas-solid interface, which is 8.36 times that of the pristine ZnIn2S4.