Highly Efficient Photocatalytic Hydrogen Evolution over Mo-Doped ZnIn2S4 with Sulfur Vacancies

The introduction of impure atoms or crystal defects is a promising strategy for enhancing the photocatalytic activity of semiconductors. However, the synergy of these two effects in 2D atomic layers remains unexplored. In this case, the preparation of molybdenum-doped thin ZnIn2S4-containing S vacancies (Mo-doped Sv-ZnIn2S4) is conducted using a one-pot solvothermal method. The coordination of Mo doping and S vacancies not only enhances visible light absorption and facilitates the separation of photogenerated carriers but also provides many active sites for photocatalytic reactions. Meanwhile, the Mo-S bonds play function as high-speed channels to rapidly transfer carriers to the active sites, which can directly promote hydrogen evolution. Consequently, Sv-ZnIn2S4 with an optimized amount of Mo doping exhibits a high hydrogen evolution rate of 5739 mu mol g(-1) h(-1) with a corresponding apparent quantum yield (AQY) of 21.24% at 420 nm, which is approximately 5.4 times higher than the original ZnIn2S4. This work provides a new strategy for the development of highly efficient and sustainable 2D atomic photocatalysts for hydrogen evolution.

Automated summary

Doping impure atoms or introducing crystal defects can enhance the photocatalytic activity of semiconductors. In this study, a molybdenum-doped thin ZnIn2S4 material was prepared using a one-pot solvothermal method, in which the coordination of Mo doping and S vacancies enhanced visible light absorption, facilitated the separation of photogenerated carriers, and provided active sites for photocatalytic reactions. The optimized Mo-doped Sv-ZnIn2S4 exhibited a significantly higher hydrogen evolution rate compared to the original ZnIn2S4, demonstrating a new strategy for developing efficient 2D atomic photocatalysts for hydrogen evolution.