Type II Heterojunction Formed by 3D Flower-like Microspheres of BiOBr/NH2-Fe-MOF with High Photocatalytic Degradation of RhB via Visible Light

Using the solvothermal method, a novel three-dimensional flower-like microsphere structure composite BiOBr/NH2-Fe-MOF was prepared with type II heterojunction through the combination between BiOBr and NH2-Fe-MOF, which had 20% enhancement of specific surface area and effectively suppressed the recombination of photoinduced electron-hole pairs. After 40 min of visible light irradiation, the degradation rate constant of BiOBr/NH2-Fe-MOF-2 reached 0.08507 min(-1), which was 5.29 times higher than that of BiOBr and 11.34 times higher than that of NH2-Fe-MOF. BiOBr/NH2-Fe-MOF-2 represented the highest degradation efficiency of rhodamine B, up to 98.3%. After 6 cycles of experiments, the degradation rate could still maintain 85%, which is superior to the research results of most photocatalysts reported in the literature in the last 5 years. The mechanistic study suggested that O-center dot(2)- was the main active species in RhB photocatalytic degradation. The combination of NH2-Fe-MOF with BiOBr in this study provides a new method for the rapid degradation of dye pollutants.