BiVO4/Bi2O3 submicrometer sphere composite: Microstructure and photocatalytic activity under visible-light irradiation

Bismuth vanadate (BiVO4) powders were synthesized by homogeneous precipitation method with different surface dispersants. Bi(NO3)(3)center dot 5H(2)O and NH4VO3 were utilized as starting materials to synthesize BiVO4 particles with the edge length of about 100-150 nm. Bismuth oxide (Bi2O3) Was prepared by decomposing Bi(NO3)(3)center dot 5H(2)O at 600 degrees C. Techniques of X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM) and ultraviolet-visible diffuse reflectance spectra (UV-vis DRS) have been employed to characterize the as-synthesized materials. The results showed that the structure and morphology Of BiVO4 were various using different surface dispersant. We have also investigated the photocatalytic degradation of rhodamin B which showed that BiVO4/Bi2O3 possessed a high photocatalytic activity under visible-light irradiation. The photocatalytic activity is in close relation with the surface dispersant about BiVO4 synthesis. The result was better using N,N-dimethylacetamide (DMA) than using N-methyl-2-pyrrolidone. The inverse proportion between BiVO4 and Bi2O3 was also important for the photocatalysis. (C) 2008 Elsevier B.V. All rights reserved