“Electron collector” Bi19S27Br3 nanorod-enclosed BiOBr nanosheet for efficient CO2 photoconversion

Although CO2 photoreduction is a promising method for solar-to-fuel conversion, it suffers from low charge transfer efficiency of the photocatalysts. To improve the CO2 photoreduction performance, introduction of electron-accumulated materials on the photocatalyst surface is considered an effective method. In this study, the Bi19S27Br3/BiOBr composites were designed and synthesized. The Bi19S27Br3 nanorod in this photocatalytic system acts as an electron-accumulated active site for extracting the photogenerated electrons on the BiOBr surface and for effectively activating the CO2 molecules. As a result, Bi19S27Br3/BiOBr composites exhibit the higher charge carrier transfer efficiency and further improves the CO2 photoreduction performance relative to that of pure Bi19S27Br3 and BiOBr. The rate of CO formation using Bi19S27Br3/BiOBr-5 is about 8.74 and 2.40 times that using Bi19S27Br3 and BiOBr, respectively. This work provides new insights for the application of Bi19S27Br3 as an electron-accumulating site for achieving high photocatalytic CO2 reduction performance in the future.