Preparation and Photocatalytic Capacity Evaluation of TiO₂/BiVO₄ Nanocrystalline Heterojunctions

TiO₂/BiVO₄ heterojunction nanostructures were successfully synthesized via a facile hydrothermal synthesis coupling with impregnation strategy to enhance the visible-light-driven photocatalytic properties of BiVO₄ nanocrystals. The samples were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM) and UV-vis diffuse reflectance spectra (DRS), as well as evaluated via photocatalytic test. The experimental results reveal that these TiO₂/BiVO₄ heterojunction nanostructures exhibit higher visible-light photocatalytic activities than both the individual BiVO₄ nanocrystals and TiO₂ for the degradation of model dye methylene blue. The optimum composition of TiO₂ was 70% (mass ratio). The enhanced photocatalytic efficiencies are attributed to the enhancement of the wide spectrum responsive. The nanostructures are expected to show considerable potential applications in solar-driven waste water treatment.