Synthesis of a Novel Photocatalyst MVO4/g-C3N4 (M = La, Gd) with Better Photocatalytic Activity for Tetracycline Hydrochloride Degradation under Visible-Light Irradiation

In this study, novel photocatalysts MVO4/g-C3N4 (M = La, Gd) were prepared by the hydrothermal method, through which different loading amounts of 10–50%MVO4 and g-C3N4 were mixed and ultrasonically oscillated to gain heterojunction catalysts. All the samples were characterized by XRD, SEM, TEM, FT-IR, XPS, Us-vis, and PL to ensure the successful integration of LaVO4 and GdVO4 with g-C3N4. The obtained results showed that MVO4/g-C3N4 could effectually improve the separation efficiency of photogenerated carriers during the photodegradation process, thus improving the photodegradation efficiency, while among them, 40%GdVO4/g-C3N4 showed the best photocatalytic performance and degradation of tetracycline hydrochloride, reaching up to 91% for 3 h, which was 3.64 times higher than pristine g-C3N4. From the discussed results above, the possible mechanism of the photodegradation process was put forward. This study supplies a promising method to gain g-C3N4-based photocatalysts for antibiotics removal.