Simple room temperature synthesis of oxygen vacancy-rich and In-doped BiOBr nanosheet and its highly enhanced photocatalytic activity under visible-light irradiation

Abstract

Bismuth oxyhalide photocatalysts that exhibit excellent photocatalytic activity with excellent stability have attracted much attention due to their unique optical and structural properties. In this work, oxygen vacancy rich indium (In)-doped BiOBr nanosheet was successfully synthesized with different amounts of indium by a simple room temperature hydrolysis method without any toxic precipitation chemicals and/or any capping agent. All the as-synthesized photocatalysts were systematically characterized using various techniques, and tested for their photocatalytic activity. Among all, In-15-BiOBr with 15 mol.% In precursor relative to total In and Bi precursors showed the best photocatalytic activity. In-15-BiOBr completely degraded 10 ppm Rohdamine B dye aqueous solution within only 15 min with a rate of 4.7 times faster than the pure BiOBr. It also showed excellent photocatalytic activity by degrading 10 ppm Neutral red dye within 20 min with a rate of 5.1 times faster than the pure BiOBr. The highly enhanced photocatalytic activity shown with In doping was ascribed to lower charge transfer resistance and high charge separation of the as-prepared In-doped BiOBr photocatalyst. A possible photocatalytic RhB degradation mechanism with In-15-BiOBr using visible light was proposed.