Defect-driven selective oxidation of MoS2 nanosheets with photothermal effect for Photo-Catalytic hydrogen evolution reaction

Surface oxidation engineering has been regarded as a fascinating strategy to construct MoS2-based catalyst. However, it is still challenging to precisely control the oxidation degree of MoS2 to improve its photo-catalytic hydrogen evolution reaction (PHER) activity. In this work, we monitor the defect-driven spontaneous oxidation behavior of MoS2 in an aqueous solution to optimize the PHER performance of MoS2. After exposing to the ambient atmosphere for several weeks at room temperature, defective MoS2 in solution undergoes dramatic aging effects including morphology and component evolution. The oxide-MoS2 catalyst exhibits extraordinary PHER activity with 7.85 mmol g−1h−1 under dual xenon lamp, which is 3.25 times higher than of the prefect 2H-MoS2. The synergistic effect from optimized electronic structure, the intrinsic activity of the active sites and prominent photothermal effect of MoS2 with a certain degree of oxidation greatly enhances the photo-catalytic activity. This work provides a new pathway to control the physicochemical properties and catalytic performance of MoS2-based catalysts by the defect-driven selective oxidation.