Oxygen-enriched vacancy spinel Mn-Co oxides by deep thermal reduction for enhanced antibiotics degradation efficiency

In this research work, flower-like MnCo 2 O 4.5 was synthesized by introducing a short-chain surfactant as a surface-active agent. This structure was utilized as a precursor, and a gas atmosphere pyrolytic deep reduction strategy was employed to construct a sea urchin-like catalyst (DTR-V o -MCO) with abundant oxygen vacancies. A series of characterizations were conducted to reveal the catalyst's microstructure and crystal phase composition. DTR-V o -MCO achieved more than 90% degradation of OTC within 10 min, and the efficiency was 1.5 times that of V p -MCO. The substantial presence of oxygen defects on the DTR-V o -MCO surface expedited charge transfer processes, resulting in a remarkable enhancement of PMS activation efficiency. Electron paramagnetic resonance spectroscopy (EPR) and radical quenching experiments indicated that the contributions of radicals to oxytetracycline (OTC) degradation were in the order of 1 O 2 > SO 4 •– > O 2 •– >  • OH. 1 O 2 and SO 4 •– played dominant roles in OTC degradation. The possible oxytetracycline degradation pathways were proposed based on LC-MS analysis. In summary, this work presents an efficient method for a highly oxygen-deficient catalyst, expanding the application of binary transition metal materials in environmental remediation.