Ionic liquid-assisted solvothermal construction of NH2-MIL-125(Ti)/BiOBr heterojunction for removing tetracycline under visible light

In this article, we reported a method for synthesizing cluster-like NH2-MIL-125(Ti)/BiOBr (NMT/B) Z type heterojunction composite materials with different content by using ionic liquid as bromine source assisted solvothermal method. In visible light, the photocatalytic activity of the materials was analyzed by degradation of tetracycline. Characterize the prepared composite material by XRD, FTIR, SEM, TEM, XPS, UV-vis diffuse reflection spectra (DRS). The result proved that the NH2-MIL-125(Ti) (NMT) nanosheets were tightly loaded on the BiOBr surface. NMT/B composite materials showed higher catalytic activity than monomer materials. The removal rate of TC reached 88% in 90min, which was 3 times and 5.7 times that of the monomer NMT and BiOBr monomer materials, respectively. In the catalytic process, -O-2(-) and h(+) are the main active substances that degrade pollutants. This is proved by free radical capture experiments. It could be inferred that the improved photocatalytic activity of NMT/B composites was contributed to the good energy band structure and the formation of Z-type heterojunctions in close contact, which greatly facilitates the photogenerated carrier and hole migration and dissociation. Cycle experiment proved that the prepared composite material has excellent stability, which indicated that it had a good prospect in practical applications.