A novel Z-type BiOCl/Ni-MOF-74 heterojunction with coral reef-like structure for photodegradation of tetracycline and rhodamine B and degradation pathway analysis

The presence of defects in BiOCl, caused by its wide bandgap, hampers its ability to effectively respond to visible light. In this paper, Z-type BiOCl/Ni-MOF-74 (B/N) heterojunctions were synthesized using the hydrothermal method, The crystal structure, morphological characteristics, and physicochemical properties of the composite material were tested through multiple characterization methods, demonstrating Ni-MOF-74 (N-M-74) successful loading on BiOCl. For the degradation, tetracycline (TC) and rhodamine B (RhB) was chosen, and the degradation performance of the synthesized B/N system was assessed under visible light. BiOCl/Ni-MOF-74-7 wt% (B/N-7) showing optimal degradation performance, and the degradation rate of TC and RhB within 100 min was 93% and 97%, respectively. This is due to the composition of heterojunctions, which forms a good band structure and prevents the rebuild of photogenerated charge carriers. The free radical capture experiment and ESR technique demonstrated that •O2− and h+ were crucial in the degradation of TC and RhB. Finally, a Z-type mechanism is proposed to explain the mechanism. 3D Fluorescence Spectra (3D EEMS) and Liquid Chromotography with Mass Spectrometry (LC-MS) were combined to analyze the degradation process.