Ni, In co-doped ZnIn2S4 for efficient hydrogen evolution: Modulating charge flow and balancing H adsorption/desorption

Element doping is an excellent strategy to promote charge separation and reaction kinetics of photocatalyst, which plays significant role in accelerating the sustainable energy development process. Herein, Ni, In co-doped ZnIn2S4 photocatalyst was prepared by a microwave-assisted solvothermal method. The rapid crystallization of ZnIn2S4 resulted in partial In atoms substituted Zn atom during the formation of [ZnS]4 layer. In doping in tetrahedral Zn sites increases the electron delocalization around In sites, hence reduces the electronic potential wells along Z axis. Ni doping in tetrahedral Zn sites decreases the negative charge on the S sits, which balances the H adsorption/desorption, further boosting the photocatalytic activity. As a result, Ni, In co-doped ZnIn2S4 possess an optimal photocatalytic H2 evolution property of 21.94 μmol·h−1, which is nearly 1.8 and 6.1 times of In-ZnIn2S4 (11.78 μmol·h−1) and ZnIn2S4 (3.6 μmol·h−1).