Boosting the activation of Peroxymonosulfate and the degradation of metronidazole over FeCo2O4 quantum dots anchored on β-FeOOH Nanosheets: Inspired from octahedral Co(II) with missing angle

Peroxymonosulfate (PMS) activation by bimetallic Co/Fe oxides, especially spinel FeCo2O4, is a promising way in decontaminating organic pollutants wastewaters. However, it suffers from low efficiency and the intrinsic catalytic mechanisms are still poorly understood. Therefore, we applied lattice VOs (oxygen vacancies) adjustment strategy to construct octahedral Co(II)–enriched FeCo2O4 quantum dots anchored on β-FeOOH nanosheets composite (Co(II)-FCQDs/FNS) for boosting PMS during degradation of Metronidazole (MNZ), pure (FCQDs) was studied as comparison. As result, PMS/Co(II)-FCQDs/FNS system, 5–30 mg·L−1 MNZ could be completely degraded within 5 min with usage 0.05 g·L−1 catalyst, 100 reached 99.92% 40 utilization 62.90% at same condition, whose rate constant 6.45 times than that FCQDs/PMS system. The electron paramagnetic resonance (EPR) quenching experiments indicated /Co(II)-FCQDs/FNS system radical-based (sulfate radicals (SO4•−), hydroxyl (•OH) superoxide radical (O2•−) oxidation process. Density functional theory (DFT) calculation revealed generation Co(II) derived oxygen vacancies, improved charge transfer while providing new channel Co(II)/Fe(II) surface FeCo2O4. Simultaneously, strengthened adsorption HSO5− increased number unpaired electrons, thus performance. In addition, influence reaction parameters water matrix were investigated. Finally, pathway proposed toxicity intermediates also assessed. This work expected facilitate design application wastewater.