Development of a magnetic Ce-Zr bimetallic MOF as an efficient catalytic ozonation mediator: Preparation, characterization, and catalytic activity

Abstract

We studied the catalytic activity of a series of magnetic CeZrUiO-66 Metal-Organic Framework (MOF) composites (Fe3O4/CeZrUiO-66) for ciprofloxacin (CIP) degradation by catalytic ozonation. The most efficient catalyst for the degradation of ciprofloxacin is the composite with a 30:70 ratio of Fe3O4:CeZrUiO-66, achieving a 97 % elimination yield within 30 min. The kinetics of CIP degradation in the single ozonation process (SOP) and the catalytic ozonation process (COP) were 0.019 and 0.072 min−1, respectively. The degree of CIP mineralization in the COP was around 54 %, which is higher than that in the SOP under similar conditions. The evaluation of reaction efficiency in the presence of various inhibitors revealed that OH radicals are the main reactive species, although O2− also contributed to CIP degradation. Examination of the generated intermediates using liquid chromatography-mass spectrometry (LC-MS) determined the degradation mechanism pathways in the catalytic ozonation process using the prepared new MOF. The stability of the prepared magnetic composite after several consecutive runs confirms the catalyst's reusability and the possible prospects of further application of the composite catalyst.