The role of the Co reduction and Zn evaporation of ZnCo-MOF carbonization in peroxymonosulfate activation for levofloxacin purification from wastewater

Nowadays, emerging pollutants have been attracting many interests from the researchers. Many attentions are being paid to sulfate based advanced oxidation process for purification of emerging pollutants degradation, what depended on the activity in peroxymonosulfate (PMS) activation. In this work, the Zinc and Cobalt bimetallic zeolite imidazole framework (ZnCo-MOF) was conducted as precursor for preparing a novel magnetic ZnxCoy-CN-T through carbothermal reduction. The ZnxCoy-CN-T was further used to activate PMS for degrading levofloxacin (LEV) as a typical emerging pollutant. XRD, SEM, XPS and Raman spectra analysis were used to characterize the ZnxCoy-CN-T. Carbothermal reduction of ZnCo-MOF at 900 °C leads to the generation of zero-valent cobalt and the volatilization of Zn. Meanwhile, the volatilization of Zn not only brings about the adjacent diffusion of the Co atom but also constructs porous carbon (CN) for anchoring the well dispersed Co nanocluster. The Zn1Co5-CN-900 performed the high activity in PMS activation for LEV degradation with favorable efficiency and rate of 98.3% and 0.228 min−1 within 60 min, respectively. The Zn1Co5-CN-900 could be recycled five times with preferable stability and magnetism. The possible degradation pathways were proposed by identifying the intermediate products through liquid chromatography-mass spectrometry (LC-MS) analysis. In summary, a kind of zero-valent cobalt nanocluster anchored on CN was designed to construct a promising Zn1Co5-CN-900/PMS system for LEV degradation with favorable activity and reusability.