Structure, morphology and photocatalytic performance of europium and fluorine co-doped bismuth vanadate

Abstract

In this paper, Eu/F co-doped bismuth vanadate photocatalysts with different doping ratios were prepared by a hydrothermal method, and their microscopic morphology, crystal structure, light absorption and photocatalytic performance were investigated. Part of the F in the Eu/F co-doped samples might be doped to replace O in the BiVO₄ lattice, while Eu³⁺ ions replaced Bi³⁺ ions, which led to a difference in the morphology and internal structure. XRD and Raman spectroscopy characterization showed that the crystal structures of the samples were all monoclinic scheelite type, and contained a certain tetragonal scheelite type, and the crystallinity was good. The Eu/F co-doped samples exhibited better photoactivity under UV-Vis light. The recombination rate of the photogenerated carriers in the Eu/F co-doped samples was obviously reduced, but it showed a serious concentration dependence on the doping species. Under visible light irradiation, Eu/F co-doped samples (R = 0.75) had the best degradation effect on methylene blue (MB). In addition, the degradation mechanism of the photocatalyst was also explored. ˙O₂⁻ and h⁺ were the main active species affecting the degradation of MB by Eu/F–BiVO₄.