Comparative study on photocatalytic performances of crystalline alpha- and beta-Bi2O3 nanoparticles under visible light

Abstract

alpha- and beta-Bi2O3 nanoparticles were synthesized in the presence of either urea or polyethylene glycol. The XRD, TEM, and Raman analysis indicated that alpha-(monoclinic)Bi2O3 nanoparticles were obtained using either' sol-gel or hydrothermal method in the presence of urea; however beta-(tetragonal) phase of Bi2O3 was formed using hydrothermal method in the presence of polyethylene glycol. The beta-Bi2O3 nanoparticles exhibited higher photocatalytic activity than alpha-Bi2O3. MB was completely photodegraded after 6 h of visible light illumination using beta-Bi2O3 photocatalyst whereas only 30% was photodegraded using alpha-Bi2O3. The photodegradation rate of beta-Bi2O3 was 5.7 times greater than that alpha-Bi2O3 nanoparticles. (C) 2015 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.