Preparation of Ce Doped BiVO4 Magnetic Composite and Its Photocatalytic Degradation Performance for Rhodamine B

A Ce-doped photocatalytic composite with easy solid–liquid separation capability was prepared and a heterojunction was constructed between BiVO4 and Fe3O4 via a co-precipitation method. A variety of characterization techniques were employed, such as X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), ultraviolet–visible spectroscopy (UV-vis), transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDS), as well as other related methods. Its photocatalytic performance for the degradation of Rhodamine B (RhB) was also studied. The results indicate that the photocatalytic efficiency of BiVO4/Fe3O4 is 1.4 times that of the pure BiVO4 matrix. In particular, the photocatalytic efficiency of Ce1.5%-BiVO4/Fe3O4 was 2.2 times higher than that of the pure BiVO4 matrix, and a 100% degradation rate of RhB was achieved within 30 min. The introduction of Fe3O4 not only forms a heterojunction with BiVO4, increasing the active sites and surface oxygen vacancies of the material and effectively suppressing the recombination of photogenerated electron (e-)-hole (h+) pairs, but it also enables the rapid separation of the material from the wastewater solution by the magnetic properties of Fe3O4. Additionally, the partial substitution of Ce for Bi in the BiVO4 lattice reduces the bandgap energy, which enhances the utilization efficiency of visible light and improves the photocatalytic performance of the composite material. The mechanism of RhB degradation by Ce1.5%-BiVO4/Fe3O4 composite materials is also analyzed in this study. Quenching experiments and EPR tests revealed that h+ and ·O2- were the primary reactive species in the degradation process.