In situ anion exchange synthesis of beta-Ag2MoO4/AgBr heterojunctions with enhanced photocatalytic activity and stability

beta-Ag2MoO4/AgBr heterojunctions were successfully prepared by a facile ultrasonic-assisted in-situ anionexchange method, anchoring sphere-like AgBr particles on the surface of octahedral beta-Ag2MoO4 . Photocatalytic performances of the obtained samples were studied by the degradation of Rhodamine B (RhB), tetracycline hydrochloride (TC) and 4-Chlorophenol (4-CP) under visible-light irradiation. Results proved that the introduction of beta-Ag2MoO4 had improved the photocatalytic activity of AgBr, and 5% beta-Ag2MoO4/AgBr composites exhibited the highest degradation efficiency with degrading 98.4% RhB during 5 min, which was about 1.05 times and 13 times higher than that of pure AgBr and beta-Ag2MoO4, respectively. Meanwhile, cycling test of as-prepared samples had indicated the excellent cycling stability of asprepared samples. The obviously enhanced photocatalytic activity and stability could be attributed to the well-matched binding energies and heterostructure between AgBr and beta-Ag2MoO4, where the utilization efficiency of solar light was improved, and charge separation at the heterojunction interfaces was accelerated. Besides, trapping experiments implied that holes and center dot O2- were the predominant active species during the degradation process of RhB. Meanwhile, a possible mechanism for the degradation of organic pollutants by beta-Ag2MoO4/AgBr photocatalysts was proposed. (C) 2018 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.