Electrochemical performance and enhanced photocatalytic activity of Ce-doped BiVO₄ under visible light irradiation

Highlights: • Ce-BiVO₄ was synthesized via a simple precipitation-impregnation method. • Photo-generated electrons transfer from the BiVO₄ to the Ce⁴⁺ ions. • The enhanced interfacial electron transfer for Ce-BiVO₄ was observed using EIS and photocurrent. • The enhanced activity of Ce-BiVO₄ is mainly attributed to the increased charge separation. - Abstract: Ce-BiVO₄ composites have been synthesized via a simple precipitation-impregnation method and were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), UV–vis diffuse reflectance spectrum (DRS), electrochemical impedance spectrum (EIS) and photocurrent. All the BiVO₄ and Ce-BiVO₄ samples are composed of monoclinic scheelite BiVO₄. Compared to BiVO₄, the increased photocurrent and decreased diameter of the semicircle have been observed for Ce-BiVO₄, indicating that the Ce-doping can enhance interfacial electron transfer for Ce-BiVO₄. Ce-BiVO₄ composites show enhanced activity in the photocatalytic degradation of rhodamine B under visible light irradiation in comparison with P25 and pure BiVO₄, and 1.0%Ce-BiVO₄ shows the best photocatalytic activity because of its enhanced light absorption, narrowed bandgap and improved separation of the photogenerated electron–hole pairs, which was achieved as a result of photogenerated electrons transfer from the BiVO₄ to the Ce⁴⁺ ions.