Insights into the function of metallic 1T phase tungsten disulfide as cocatalyst decorated zinc indium sulfide for enhanced photocatalytic hydrogen production activity.

Improving the separation efficiency of carriers is an important part of enhancing photocatalytic activity. Herein, we successfully decorated metallic 1T phase tungsten disulfide (1T-WS) on the surface of zinc indium sulfide (ZnInS) and investigated the synergistic effect of 1T-WS on ZnInS. The characterization results show that 1T-WS improves the light absorption capacity and utilization efficiency, increases the catalytic active site, improves the photogenerated charge separation efficiency, and optimizes the reduction potential of ZnInS. Theoretical calculations show that compared with ZnInS, 1T-WS/ZnInS has a smaller adsorption Gibbs free energy of the intermediate state H*, which is conducive to the catalytic reaction. Under simulated solar irradiation, the hydrogen (H) production rate of 1T-WS/ZnInS with a loading of 12 wt% reaches 30.90 mmol h g, which is 3.38 times higher than that of single ZnInS (9.13 mmol h g). In addition, the apparent quantum efficiency of 1T-WS/ZnInS with a loading of 12 wt% reaches 21.14 % under monochromatic light at a wavelength of λ = 370 nm. This work analyzes the light absorption and carrier separation to the catalytic site, and elucidates the mechanism for the enhancement of the photocatalytic hydrogen production performance.