Enhanced photocatalytic performance of BiOBr/NH-MIL-125(Ti) composite for dye degradation under visible light.

Metal-organic frameworks (MOFs) are considered as suitable materials for various applications in the area of photocatalysis. On the other hand, 2D BiOBr materials are efficient for the photodegradation of organic dyes under visible light illumination. In this work, BiOBr/NH-MIL-125(Ti) composite photocatalysts with different NH-MIL-125(Ti) content were prepared by incorporating NH-MIL-125(Ti) with BiOBr using a co-precipitation method. A series of characterizations confirmed the strong synergistic effect between BiOBr and NH-MIL-125(Ti). In rhodamine B (RhB) degradation experiments, the composite photocatalyst with a mass percent of 7 wt% NH-MIL-125(Ti) exhibited an improved photocatalytic activity compared to pristine BiOBr and NH-MIL-125(Ti). Furthermore, the enhanced photocatalytic performance under visible light illumination could be attributed to the Ti-Ti intervalence electron transfer and synergistic effect between NH-MIL-125(Ti) and BiOBr, and also resulted in a separation efficiency of photo-generated electron-hole pairs during the photocatalytic reaction. This study can open up numerous opportunities for the development of various MOF-based visible light photocatalysts when combined with 2D bismuth oxyhalide materials for applications in environmental cleaning.