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

Abstract Bismuth vanadate (BiVO 4 ) powders were synthesized by homogeneous precipitation method with different surface dispersants. Bi(NO 3 ) 3 ·5H 2 O and NH 4 VO 3 were utilized as starting materials to synthesize BiVO 4 particles with the edge length of about 100–150 nm. Bismuth oxide (Bi 2 O 3 ) was prepared by decomposing Bi(NO 3 ) 3 ·5H 2 O at 600 °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 BiVO 4 were various using different surface dispersant. We have also investigated the photocatalytic degradation of rhodamin B which showed that BiVO 4 /Bi 2 O 3 possessed a high photocatalytic activity under visible-light irradiation. The photocatalytic activity is in close relation with the surface dispersant about BiVO 4 synthesis. The result was better using N,N-dimethylacetamide (DMA) than using N-methyl-2-pyrrolidone. The inverse proportion between BiVO 4 and Bi 2 O 3 was also important for the photocatalysis.