ZIF-67-derived carbon@Co3S4/CoSO4/MnO polyhedron to activate peroxymonosulfate for degrading levofloxacin: Synergistic effect and mechanism

In this work, a carbon-doped Co3S4/CoSO4/MnO catalyst (C@CoSOMn) was prepared in this work by using ZIF-67 as the template. The prepared catalyst was used to degrade levofloxacin (LEVO) by activating peroxymonosulfate (PMS). The optimized catalyst could degrade 97.73 % LEVO within 20 min with a rate constant of 0.294 min−1. The combination of water-soluble CoSO4 and Co3S4 made more Co sites accessible to PMS for lasting decomposition to produce active species. Moreover, Mn species with low redox potential could promote the regeneration of Co3+ and the activation of PMS. The doped carbon could facilitate the transfer of electron. Superoxide radicals (⋅O2−), bulk and surface hydroxyl radicals (•OH), surface sulfate radicals (SO4•−), and electron transfer process, especially the singlet oxygen (1O2) were involved in the LEVO degradation. This study sheds light on the synergism between the Co-based sulfide and the Mn oxide in the activation process of PMS, and might prompt the development of other ZIF-67-derived hybrid materials for environmental remediation.