Dual cocatalysts and vacancy strategies for enhancing photocatalytic hydrogen production activity of Zn3In2S6 nanosheets with an apparent quantum efficiency of 66.20%

Converting solar energy into hydrogen energy is a feasible means to solve the current energy crisis. However, developing an excellent photocatalyst with high light utilization and stability for hydrogen production remains a great challenge. In this work, CoS2 nanoparticles as cocatalysts are growth on Zn3In2S6 nanosheets with abundant sulfur vacancies for hydrogen evolution, and the optimal rate of hydrogen evolution is as high as 5.69 mmol h-1 g-1 in the absence of noble metal co-catalyst Pt, which is 2.87 and 2.29 times that of CoS2/Zn3In2S6 (with few sulfur vacancies) and Zn3In2S6 (with rich sulfur vacancies). In addition, the hydrogen production rate of CoS2/Zn3In2S6 composite (with rich sulfur vacancies and 1 wt% Pt) is 24.17 mmol h-1 g-1, which is 4.25 and 1.90 times that of CoS2/Zn3In2S6 (with rich sulfur vacancies) and 1%-Pt/Zn3In2S6 (with rich sulfur vacancies), respectively. The apparent quantum efficiency (AQE) of CoS2/Zn3In2S6 composite (with rich sulfur vacancies and 1 wt% Pt) reaches 66.20% under light irradiation at the wavelength of 370 nm. Above all indicate that dual cocatalysts (CoS2 and Pt) and sulfur vacancies can promote the efficient hydrogen evolution activity of Zn3In2S6 nanosheets. This work will provide new ideas and insights for the development of photocatalytic hydrogen production technology.