Facile synthesis of β-Bi2O3/Bi2O2CO3 nanocomposite with high visible-light photocatalytic activity

beta-Bi2O3/Bi2O2CO3 composite nanosheets are synthesized via a rational heat-treatment of Bi2O2CO3 precursor. The precursor transforms to beta-Bi2O3/Bi2O2CO3 composites and alpha-Bi2O3 phase under different calcination conditions. The photocatalytic activities are evaluated and compared through the photodegradation of methylene blue (MB) under visible-light irradiation. beta-Bi2O3/Bi2O2CO3 composites exhibit much higher photodegradation activity than Bi2O2CO3 and alpha-Bi2O3 products. The significant enhancement is attributed to the formation of beta-Bi2O3/Bi2O2CO3 heterojunctions, which is favorable for the low recombination rate of the electron-hole pairs. (C) 2014 Elsevier B.V. All rights reserved.