Hydrothermal synthesis of BiOxBry/BiOmIn/GO composites with visible-light photocatalytic activity

Bismuth oxyhalides (BiOX, X = F, Cl, Br, and I) represent a potential family for photocatalysis. However, BiOX materials suffer from the fast recombination of photogenerated electrons and holes. Therefore, it is highly desired to enhance the photogenerated charge separation of BiOX for efficient photocatalysis. Bismuth oxybromide/bismuth oxyiodide/graphene oxide (BiOxBry/BiOmIn/ GO) composites were synthesized by a simple hydrothermal method. The prepared photocatalysts were characterized by XRD, TEM-EDS, DRS, FT-IR, BET, PL, and XPS. The introduction of GO to the composites (BiOxBry/BiOmIn/GO) enhanced the visible-light photocatalytic activities in the degradation of crystal violet (CV). The photocatalytic activity of Bi4O5Br2/BiOI/GO showed a maximum rate constant of 1.1619 h−1, 3 times higher than that of Bi4O5Br2/BiOI. Further investigation of the photocatalytic activity of the Bi4O5Br2/BiOI/GO composites was performed on rhodamine-B (RhB). 98% degradation of RhB was achieved upon exposure to visible-light irradiation for 2 h. The Bi4O5Br2/BiOI/GO composites exhibited durable photocatalytic activity and chemical stability, as shown by recycling experiments and their XRD patterns. •OH and •O2− appeared to play a primary role in the CV degradation by BiOxBry/BiOmIn/GO photocatalysts according to the performed scavenger experiments. The plausible photocatalytic mechanism for the BiOxBry/BiOmIn/GO composites was discussed. The present BiOxBry/BiOmIn/GO study demonstrate the prospects of the prepared photocatalysts for water treatment applications.