A controlled anion exchange strategy to synthesize core-shell β-bismuth oxide/bismuth sulfide hollow heterostructures with enhanced visible-light photocatalytic activity

Heterojunction construction is an exciting direction to pursue for highly active photocatalysts. In this study, novel core/shell beta-Bi2O3/Bi2S3 hollow heterostructures were successfully synthesized through a simple and economical ion exchange method between beta-Bi2O3 hollow microspheres and thioacetamide (CH3CSNH2, TAA), and characterized by multiform techniques, such as XRD, XPS, SEM, TEM, BET, DRS and PL. The results indicated that the core/shell beta-Bi2O3/Bi2S3 hollow heterostructures exhibited strong absorption in visible light region and excellent photocatalytic performance for decomposing rhodamine B (RhB) compared with pure beta-Bi2O3 under visible light irradiation. Among the beta-Bi2O3/Bi2S3 photocatalysts with different molar percentage of Bi2S3 to initial beta-Bi2O3, the beta-Bi2O3/Bi2S3 (10%) heterostructures exhibited the highest photocatalytic activity, which was about 3.3 times higher than that of pure beta-Bi2O3 sample. Moreover, the study on the mechanism suggested that the enhanced photocatalytic activity mainly resulted from the role of beta-Bi2O3-Bi2S3 heterojunction formed in the beta-Bi2O3/Bi2S3, which could lead to efficient separation of photoinduced carriers. Additionally, the photosensitization of Bi2S3 and the hollow nature of B-Bi2O3 were also responsible for the high photocatalytic activity. (C) 2014 Elsevier Inc. All rights reserved.