Hybrid BiOBr/UiO-66-NH₂ composite with enhanced visible-light driven photocatalytic activity toward RhB dye degradation

Metal-organic framework (MOFs) based composites have received more research interest for photocatalytic applications during recent years. In this work, a highly active, visible light photocatalyst BiOBr/UiO-66-NH₂ hybrid composite was successfully prepared by introducing various amounts of UiO-66-NH₂ with BiOBr through a co-precipitation method. The composites were applied for the photocatalytic degradation of RhB (rhodamine B) dye. The developed BiOBr/UiO-66-NH₂ composites exhibited higher photocatalytic activity than the pristine material. In RhB degradation experiments the hybrid composite with 15 wt% of UiO-66-NH₂ shows degradation efficiency conversion of 83% within two hours under visible light irradiation. The high photodegradation efficiency of BUN-15 could be ascribed to efficient interfacial charge transfer at the heterojunction and the synergistic effect between BiOBr/UiO-66-NH₂. In addition, an active species trapping experiment confirmed that photo-generated hole⁺ and O₂ ⁻ radicals are the major species involved in RhB degradation under visible light.