Influence of cerium and iron substitution on the Bi2WO6 hierarchical microsphere and their enhanced photocatalytic degradation performance

A facile hydrothermal approach was employed to synthesize cerium and iron co-doped Bi2WO6 photocatalysts, and their photocatalytic performance for the degradation of cationic rhodamine B (RhB) and thionine (TH) dyes under UV-visible light illumination was investigated. Powder XRD investigation revealed that the Ce and Fe ions significantly influenced the Bi2WO6 crystal structure, while HR-XPS confirmed the valence states of Ce and Fe ions in the Bi2WO6 lattice. The light absorption wavelength of the co-doped samples was red-shifted when compared to the pristine Bi2WO6. The photoluminescence spectroscopy results showed that the synergistic effect of the Ce-Fe intermediate state in the Ce-Fe co-doped Bi2WO6 photocatalyst significantly reduced the recombination of photoinduced electron-hole pairs and boosted photocatalytic degradation activity. Furthermore, the stability of the best-performed catalyst was verified using recycling tests. The degrading efficiency of TH and RhB was not significantly affected after five repeated cycles. A potential mechanism for increased photocatalytic activity was also discussed.