Visible light photocatalysis: efficient Z-scheme LaFeO₃/g-C₃N₄/ZnO photocatalyst for phenol degradation

In this work, a Z-scheme LaFeO₃/g-C₃N₄/ZnO heterojunction photocatalyst with large specific surface (68.758 m²/g) and low cost (0.00035 times the cost of per gram of Au) was easily synthesized by glucose-assisted hydrothermal method. The structure, surface morphology, and optical properties of the photocatalyst were investigated. The constructed Z-scheme heterojunction catalysts can enhance the visible light absorption and carrier separation efficiency. Among these photocatalysts, the 10%-LaFeO₃/g-C₃N₄/ZnO composite possesses the premium performance for efficient degrading 97.43% of phenol within 120 min. Even after 5 cycles, it still sustains an excellent photocatalytic stability (92.13% phenol degradation). According to the XPS surface states and the capture of active species on LaFeO₃/g-C₃N₄/ZnO, the electrons would be transferred from ZnO and LaFeO₃ to g-C₃N₄. In addition, ·OH plays an important role in photocatalytic reactions for phenol degradation. Thus, the proposed possible photocatalytic reaction mechanism of Z-scheme LaFeO₃/g-C₃N₄/ZnO can provide a more economical and efficient conception for phenol degradation.