Controlled synthesis of graphitic carbon nitride/beta bismuth oxide composite and its high visible-light photocatalytic activity

g-C3N4/beta-Bi2O3 composites with high visible-light-driven photocatalytic activity were prepared through calcination of g-C3N4/Bi2O2CO3 of different proportions. They were characterized by powder X-ray diffraction (XRD), Fourier Translation infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FESEM), transmission electron microscopy TEM (high resolution transmission electron microscopy HRTEM), UV-vis diffuse reflectance spectra (UV-vis DRS) and photoluminescence spectra (PL) techniques. It was observed that the phase structure.of Bi2O3 is subject to the amount of g-C3N4 in the g-C3N4/Bi2O2CO3 precursor. Based on the results of light absorption and photocurrent measurement as well as the energy levels of beta-Bi2O3 and g-C3N4, we propose a mechanism for the degradation of organic compounds over this class of catalysts. (C) 2015 Elsevier Ltd. All rights reserved.