Construction of novel CoMoO4/AgVO3 heterojunction with abundant oxygen vacancies for efficient photocatalytic hydrogen evolution

To address the limitations of CoMoO4 photocatalysts (e.g., high recombination rate of photogenerated electronhole pairs and low light energy utilization), a novel CoMoO4/AgVO3 photocatalyst enriched with oxygen vacancies (OV) was constructed and the photocatalytic hydrogen production ability under visible light irradiation was investigated. The experimental results indicate that the hydrogen production efficiency of CoMoO4/AgVO330 reaches 3049.28 mu mol g- 1h- 1, which is 5.07 times higher than that of CoMoO4 and 8.89 times higher than that of AgVO3. Based on the XPS, UPS and DFT characterization results, it can be inferred that, since the work function of CoMoO4 compared to is lower than that of AgVO3, the electrons of CoMoO4 undergo transfer AgVO3 when the two are in contact, thus optimizing the energy band structure. In-situ XPS results further reveal that under photoexcitation conditions, the electrons of CoMoO4 are continuously transferred to AgVO3, consistent with the S-scheme electron transfer mechanism, which facilitates the spatial separation of photogenerated carriers and holes. Furthermore, the abundant OV in CoMoO4/AgVO3 enhances the capture of photogenerated electrons and promotes the hydrogen evolution reaction. S-scheme electron transfer mechanism synergizes with abundant OV to boost photocatalytic hydrogen evolution activity.