Eu2O3/Co3O4 nanosheets for levofloxacin removal via peroxymonosulfate activation: Performance, mechanism and degradation pathway

Abstract

• Eu 2 O 3 /Co 3 O 4 nanosheets were successfully synthesized. • Eu 2 O 3 /Co 3 O 4 NSs displayed excellent catalytic performance for PMS activation toward LVX degradation. • 1 O 2 played more key role in LVX degradation than •OH, SO 4 •− and •O 2 −. • The possible mechanism and degradation pathways of LVX were cleared in detail. In this study, Eu 2 O 3 /Co 3 O 4 nanosheets (NSs) were successfully synthesized and employed to degrade levofloxacin (LVX) via peroxymonosulfate (PMS) activation. Owing to the enhanced transfer efficiency of Co 2+ /Co 3+ and more adsorbed oxygen, the obtained Eu 2 O 3 /Co 3 O 4 NSs displayed better catalytic performance for PMS activation toward LVX degradation than pure Co 3 O 4 . The Eu 2 O 3 /Co 3 O 4 NSs can remove 97.93% of LVX only in 6 min via activating PMS, with a reaction rate constant (0.2346 min −1 ) , which was 2.3 folds of single Co 3 O 4 NSs (0.1003 min −1 ). Besides, Eu 2 O 3 /Co 3 O 4 exhibited good catalytic performance in presence of different inorganic anions, satisfactory stability and reusability. Singlet oxygen ( 1 O 2 ), hydroxyl radical (•OH), sulfate radical (SO 4 •− ) and superoxide radical (•O 2 − ) contributed to LVX degradation and 1 O 2 played the most key role. In addition, based on the ROSs and LVX degradation intermediates, the possible mechanism and degradation pathways of LVX were further cleared in detail. This work can provide a reference for the eco-friendly and facile preparation strategy of efficient and stable catalysts for rapid and efficient removal of recalcitrant pollutants.