Z-scheme indium sulfide/bismuth oxybromide heterojunctions with enhanced visible-light photodegradation of organics

Heterojunction photocatalysts with intimate contact are very promising for organics photodegradation due to their high efficiency in enhancing the light absorption, inhibiting the carrier recombination and improving the photogenerated electron/hole separation. In this study, we demonstrated a two-step hydrothermal method to construct indium sulfide/bismuth oxybromide (In2S3/BiOBr) heterojunctions for the first time. Importantly, the optoelectronic dynamics of carrier separation efficiency, charge transport and electron/hole recombination rate were tuned to an optimal domain through a series of experiments. As a result, the photocatalytic activity of In2S3/BiOBr heterojunctions was greatly enhanced under visible-light irradiation. The as-synthesized IS/BOB-0.2 heterojunctions exhibited the highest photocatalytic ability, which was approximately 4.75 times and 11.26 times higher than that of pure BiOBr and TiO2 P25 catalysts. This work will provide a better insight into the formation mechanism BiOBr-based Z-scheme heterojunctions with high photocatalytic performance.