In situ ion exchange synthesis of stable AgBr/Ag₃PO₄ dumbbell-like heterojunction photocatalysts with enhanced visible light photocatalytic degradation

Abstract

Novel dumb-bell-like AgBr/Ag₃PO₄ heterostructured photocatalyst was developed by a simple and efficient in situ ion exchange method in dimethyl sulfoxide (DMSO)/water mixed solvent systems at room temperature, and characterised by X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy and UV–vis diffuse reflectance spectrometry. Subsequently, the photocatalytic experiment for this heterojunction was conducted under visible light irradiation using typical organic dyes including Rhodamine B, methyl blue and methyl orange dyes as targeted pollutant, which indicate AgBr/Ag₃PO₄ exhibited higher photocatalytic activity compared with pure AgBr or Ag₃PO₄, and the highest photocatalytic activity was reached by AgBr/Ag₃PO₄ hybrid photocatalyst with 20 w% of AgBr. Moreover, Superior stability was also observed by recycling experiments indicating that heterostructured AgBr/Ag₃PO₄ is highly desirable for the remediation of organic waste-contaminated wastewaters. In addition, the possible photocatalytic mechanisms of AgBr/Ag₃PO₄ heterojunction and degradation pathways on basis of the experimental results are also proposed in detail.

Keywords:

• AgBr
• Ag₃PO₄
• AgBr/Ag₃PO₄
• heterostructure
• visible light driven
• photocatalysis

Acknowledgements

Dr. G. Tang gratefully acknowledges financial support from the QingLan Project Foundation of Jiangsu Province and Senior Engineer for Jiangsu Higher vocational colleges (2015FG058) and Dr. H. Tang gratefully acknowledges financial support from the QingLan Project Foundation of Jiangsu Province and Wuhan University of Technology, Key (2016-KF-10).