Facile aqueous synthesis of Bi4O5Br2 nanosheets for improved visible-light photocatalytic activity

Abstract

Bi4O5Br2 nanosheets have been fast synthesized via a facile aqueous method. The morphology, crystal structure, optical property, and electronic structure of the obtained samples were discussed. During the reaction process, it was found that the reaction parameters including the amount of NaBr and the amount of NaOH significantly influenced the composition and structure of the samples. The photocatalytic performance of the prepared samples was explored by degrading BPA under visible-light irradiation. Bi4O5Br2 nanosheets exhibited enhanced photocatalytic activity in comparison to BiOBr or Bi5O7Br, which can be attributed to its higher visible-light absorption and lower interface charge transport resistance. Additionally, the photocatalytic degradation mechanism over Bi4O5Br2 nanosheets was also investigated. h+ and •O2− were the main photoactive species during the visible-light photocatalytic process by quencher experiments and EPR results. This study is expected to provide new insights into the development on facile fabrication and potential application of Bi-deficient bismuth oxybromide photocatalysts.