An α-Bi2O3/BiOBr core–shell heterojunction with high photocatalytic activity

Abstract

We prepared an α-Bi₂O₃/BiOBr core–shell heterojunction via a facile in situ chemical transformation method. Ultrathin BiOBr nanosheets were observed and these were found to be evenly distributed on the surface of α-Bi₂O₃/BiOBr by SEM and TEM. The results revealed that the prepared α-Bi₂O₃/BiOBr photocatalysts were porous, and their specific surface areas were found to be raised on comparing with α-Bi₂O₃ and BiOBr. In our experiments, the photocatalytic activity of α-Bi₂O₃ was obviously enhanced when assembling with ultrathin BiOBr compared with α-Bi₂O₃/BiOBr and the individual phase. It is considered that the surface porous structure increases the specific surface areas, which improved the adsorption characteristics of α-Bi₂O₃/BiOBr. The suitable band alignment (between α-Bi₂O₃ and BiOBr) and oxygen vacancy effect can be attributed to the increased photocatalytic activity under visible irradiation.