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

Abstract

To address the limitations of CoMoO₄ photocatalysts (e.g., high recombination rate of photogenerated electron-hole pairs and low light energy utilization), a novel CoMoO₄/AgVO₃ photocatalyst enriched with oxygen vacancies (O_V) 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/AgVO₃-30 reaches 3049.28μmol 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 O_V in CoMoO₄/AgVO₃ enhances the capture of photogenerated electrons and promotes the hydrogen evolution reaction. S-scheme electron transfer mechanism synergizes with abundant O_V to boost photocatalytic hydrogen evolution activity.