Controlled fabrication and enhanced photocatalystic performance of BiVO₄@CeO₂ hollow microspheres for the visible-light-driven degradation of rhodamine B

Graphical abstract: - Highlights: • m-BiVO₄@CeO₂ hollow microspheres were firstly fabricated. • m-BiVO₄@CeO₂ was used for photocatalytic degradation of rhodamine B. • The photocatalytic activity of heterogeneous hollow microspheres is enhanced. • Photocatalytic mechanism on m-BiVO₄@CeO₂ by visible light irradiation was proposed. • Efficient separation of photoexcited charges results in enhanced catalytic activity. - Abstract: m-BiVO₄@CeO₂ hollow microspheres have been fabricated by a facile low-temperature co-precipitation method and subsequent annealing process. The composition, morphology and size of the as-fabricated m-BiVO₄@CeO₂ hollow microspheres were characterized by X-ray powder diffraction (XRD) and scanning electron microscopy (SEM). The vibrational features and the electronic state of the as-obtained m-BiVO₄@CeO₂ hollow microspheres were studied by Raman spectra and X-ray photoelectron spectroscopy (XPS). Band-gap energy of the as-prepared m-BiVO₄@CeO₂ hollow microspheres was evaluated by UV–vis spectrum. The visible-light-driven photocatalystic performances were evaluated by degradation for RhB dye molecules, demonstrating that the as-fabricated m-BiVO₄@CeO₂ hollow microspheres exhibit the enhanced photocatalystic activity, compared to the obtained pure m-BiVO₄ microspheres. The separation of photoinduced electron–hole pairs and transfer between CeO₂ and BiVO₄ has been discussed in detail, in order to have in-depth understanding on the enhanced photocatalytic performance. The results indicate that the enhanced photocatalystic activity of the as-fabricated m-BiVO₄@CeO₂ hollow microspheres is attributed to the efficient separation of the photoexcited electrons and holes