Visible light photocatalytic activity of BiVO_4 particles with different morphologies

摘要

Bismuth vanadate (BiVO_4) particles with different morphologies were synthesized by a one-step hy-drothermal process and their optical and photocatalytic properties were investigated. Their crystal structure and microstructures were characterized using X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). XRD patterns demonstrate that the as-prepared samples are monoclinic cell. FESEM shows that BiVO_4 crystals can be fabricated in different morphologies by simply manipulating the reaction parameters of hydrothermal process. The UV—visible diffuse reflectance spectra (UV-vis DRS) reveal that the band gaps of BiVO_4 photocatalysts are about 2.07-2.21 eV. The as-prepared BiVO_4 photocatalysts exhibit higher photocatalytic activities in the degradation of rhodamine B (Rh B) under visible light irradiation (λ > 420 nm) compared with traditional N-doped TiO_2 (N-TiO_2). Furthermore, wheat like BiVO_4 sample reveals the highest photocatalytic activity. Up to 100% Rh B is decolorized after visible light irradiation for 180 min. The reason for the difference in the photocatalytic activities for BiVO_4 samples obtained at different conditions were systematically studied based on their shape, size and the variation of local structure.