Synthesis of Ag/AgBr/Bi4O5Br2 Plasmonic Heterojunction Photocatalysts: Elevated Visible-light Photocatalytic Performance and Z-scheme Mechanism

The novel photocatalysts of Ag/AgBr/Bi4O5Br2 layered microspheres (AAB-LMs) were firstly constructed via the in-situ deposition and visible-light photoreduction approach. Their compositions, structures, morphologies and optical properties were characterized by various techniques. The photocatalytic efficiencies of AAB-LMs-10 were 28 and 3.4 times higher than those of Bi4O5Br2-LMs towards degrading acid orange II and aniline, respectively. The superior photocatalytic behavior of AAB-LMs benefited from efficient separation and transfer of photo-generated charges, which was mainly credited to the surface plasmon resonance effect of Ag nanoparticles and the synthetic interaction among Ag, AgBr and Bi4O5Br2. O-2(-) and h(+) were characterized as the predominant photoactive species in this AAB-LMs-photocatalysis system. Moreover, due to the presence of radical species Br-0, which was verified by the detection of bromoaniline and dibromoaniline during the photocatalytic degradation process of aniline, Z-scheme mechanism rather than the conventional heterojunction mode was more suitable to explain the enhanced photocatalytic performance of AAB-LMs.