Solar photocatalytic hydrogen production of g-C3N4/KTaO3 heterojunction for water splitting via interface engineering

Heterojunction construction is a significant method for enhancing the efficiency of electron–hole separation in photocatalysts, and it can be used to construct effective photocatalysts with visible light responses. In this study, g-C₃N₄ and KTaO₃ compounds are prepared using phase sintering and solvothermal methods. Then, the classical self-assembly process produces the KTCN composite photocatalysts. The hydrogen production rate of the KTCN composite photocatalysts (~ 842.7 μmol g⁻¹ h⁻¹) is 4.25 times faster than that of the pure g-C₃N₄ (198.2 μmol g⁻¹ h⁻¹). The formation of the heterojunction reduces the photon-generated carrier’s recombination rate, thereby improving photocatalytic efficiency. The samples were further investigated by transient photoluminescence spectroscopy. The photoluminescence intensity of the composite photocatalyst was lower than that of g-C₃N₄, indicating that the electron–hole pair complexation efficiency was significantly reduced. The heterojunction of the composite photocatalyst can significantly enhance the photoexcited interfacial charge transfer and improve carrier–hole separation efficiency. Finally, this research offers an effective method for using composite photocatalysts in photocatalytic hydrogen production.