Degradation of metronidazole by BiOBr/MIL-88B(Fe) Z-scheme heterojunction: Performance and mechanisms.

This study reports the synthesis of MIL-88B(Fe)/BiOBr, an efficient Z-scheme heterojunction photocatalyst for metronidazole (MNZ) degradation. The composite achieved a degradation efficiency of 95.2 % under visible light irradiation, outperforming the single-component catalysts (MIL-88B(Fe): 39.0 %, BiOBr: 71.5 %). Photocatalytic treatment reduced biotoxicity, indicating its potential for use and environmental safety. The degradation process of MNZ was revealed by integrating LC-MS data with Fukui function analysis. Photoelectrochemical findings indicate that MIL-88B(Fe) enhanced efficiency, facilitated charge separation, and augmented the spectral response of BiOBr. The Z-Scheme charge transfer and the function of the built-in electric field were validated by in situ XPS. DFT calculations revealed synergistic effects in the composite system, enhancing the adsorption and photocatalytic properties for MNZ. This study proposed a thorough degradation process that underpinned the development of effective photocatalysts.