Enhancing Photocatalytic Hydrogen Evolution with Oxygen Vacancy-Modified P/Ag/Ag2O/Ag3PO4/TiO2 by Using Optimized NaBH4 Reduction Strategy

The introduction of oxygen vacancies (OVs) is a promising strategy to enhance the hydrogen (H-2) evolution efficiency of photocatalysts. Sodium borohydride (NaBH4) is widely used as a reducing agent to introduce OVs, particularly in composite materials. However, its impact on H-2 evolution remains underexplored. In this study, by employing various mass ratios of NaBH4 to P/Ag/Ag2O/Ag3PO4/TiO2 (PAgT), OVs modified PAgT (R-PAgT) composites, which were synthesized and systematically characterized by XRD, FT-IR, and XPS. R-PAgT-10 with an optimal mass ratio exhibited a superior H-2 evolution efficiency and stability, maintaining its performance over 20 cycles under visible light irradiation, while the higher mass ratio of NaBH4/PAgT led to the disruption of the crystal structure with excessive OVs amounts, resulting in poor stability. This study highlighted the importance of utilizing the optimal mass ratio of NaBH4 to prepare OVs-PAgT for successful and stable H-2 evolution under visible light irradiation, which holds promise for developing efficient and durable photocatalysts for renewable energy applications.