A facile preparation strategy for hollow-structured Bi2O3/Bi2WO6 heterojunction with high visible light photocatalytic activity

A hollow-structured heterojunction consisting of Bi2WO6 nanoplatelets and Bi2O3 nanoparticles was successfully prepared by a facile solvothermal process. Bi2O3/Bi2WO6 heterojunction is the aggregate of some hollow spheres with diameter ranging from several hundred nanometers to 1.5 mu m and is connected to each other by tube-like cavums. On the basis of scanning and transmission electron microscopy observation and X-ray diffraction analysis of the samples synthesized at different reaction stages, a possible growth mechanism was proposed for the growth of hollow-structured Bi2O3/Bi2WO6 heterojunction. Its photocatalytic activity was evaluated by degradation of rhodamine B under visible-light irradiation (lambda > 400 nm). The results indicate that the hollow-structured Bi2O3/Bi2WO6 heterojunction exhibits much higher photocatalytic activity than both pure Bi2WO6 and pure Bi2O3. The improved photocatalytic performance can be ascribed to the heterojunction of Bi2O3 and Bi2WO6 in the framework in which the hierarchical hollow structure possesses good permeability and large surface area. More importantly, the hollow-structured Bi2O3/Bi2WO6 heterojunction is not only highly stable but also easy to be separated by simple sedimentation for recycle. (c) 2012 Elsevier Ltd. All rights reserved.