Improvement in photocatalytic stability of AgBr under visible light through melt processing

Over the past decade, silver bromide (AgBr, mostly as plasmonic photocatalyst: Ag/AgBr) micro or nano crystals have been extensively studied due to its superior photocatalytic activity. However, AgBr and Ag/AgBr suffer from continuous formation of Ag-0 in the photocatalytic process and the activity of the photocatalysts will be reduced rapidly, which is recognized as the bottleneck for further development and application of AgBr catalyst. In this study, we present the fabrication of melt-treated AgBr (AgBr-MT) under bromine atmosphere, which exhibits high photocatalytic activity. Surprisingly, AgBr-MT shows a giant improvement in photocatalytic stability compared to conventional powder catalysts, and the self-recovery phenomenon of AgBr was observed for the first time. The melt processing greatly reduces the unstable silver ions at the top and edge sites, and the surface reconstruction under bromine gas also contributes to the improvement of the stability of AgBr. Our findings may contribute to the development of efficient and stable silver halide-based materials and open a new perspective for this interesting material. The next research direction is to find a suitable support or prepare ultra-thin silver bromide film to further increase the effective area of AgBr. (C) 2021 Elsevier Inc. All rights reserved.