Facile Fabrication of Porous Bi_2O_3 Microspheres by Thermal Treatment of Bi_2O_2CO_3 Microspheres and its Photocatalysis Properties

摘要

β- and α-phase porous Bi_2O_3 microspheres with an average size of around 4 μm had been synthesized by thermal treatment of Bi_2O_2CO_3 microspheres at 350 and 400–500 ℃ respectively in an air atmosphere. The Bi_2O_2CO_3 microspheres had been synthesized at a temperature of 180 ℃ by a hydrothermal process using Bi(NO_3)_3 as the bismuth source with the assist of citric acid. By combining the results of X-ray powder diffraction, transmission electron microscope, scanning electron microscopy, and UV– Visible absorption spectra, the structural, morphological and optical properties characterization of the products were performed. The photocatalytic activity of the as-prepared α- and β-phase porous Bi_2O_3 microspheres have been tested by degradation ofmethylene orange under visible light, indicating that porous β-Bi_2O_3 microspheres showed enhanced photocatalytic performance compared to P25 and α-Bi_2O_3 microspheres.