Lanthanum and boron co-doped BiVO4 with enhanced visible light photocatalytic activity for degradation of methyl orange

BiVO4 photocatalysts co-doped with La and B were prepared by sol-gel method using citric acid as chelate. The samples were characterized by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), scanning electron microscopy (SEM), Brumauer-Emmett-Teller (BET), UV-Vis diffuse reflectance spectra (DRS) and the photocatalytic activity was investigated by photocatalytic degradation of methyl orange (MO). The results showed that boron and lanthanum ions incorporated into the lattice of BiVO4, and co-doping led to more surface oxygen vacancies, high specific surface areas, small crystallite size, narrow band gap and intense light absorbance in visible region. And the doped La(III) ions could help the separation of photogenerated electrons. Compared with BiVO4 and B-BiVO4, the photocatalytic activity of La-B co-doped BiVO4 was remarkably improved due to the synergistic effects of the co-doped ions. The degradation rate of MO in 60 min was 98.4% when La doping content was 0.05 mol.%, which was much higher than that of pure BiVO4(20%) and B-BiVO4(37%).

MO degradation under visible light illumination for 50 min in the presence of B-BiVO4 with various europium doping, pure BiVO4 and without photocatalyst (a) and ln(C0/C) versus time for B-BiVO4 doping concentration (b)(1) Blank; (2) Pure BiVO4; (3) B-BiVO4; (4) 0.01La-B-BiVO4; (5) 0.02La-B-BiVO4; (6) 0.05La-B-BiVO4; (7) 0.08La-B-BiVO4Figure optionsDownload full-size imageDownload as PowerPoint slide