Facile synthesis of defect-rich interfacial Mo/MoO2 for efficient peroxymonosulfate activation and refractory pollutants degradation

Peroxymonosulfate-based advanced oxidation process (PMS-AOP) has shown great potential in sewage purification, and catalyst development capable of efficient PMS activation is a key while challenging element. Herein we reported a facile electro-explosive route to synthesize the oxygen vacancy (Vo)-enriched Mo/MoO2 without using chemical reagents. The detailed studies suggested that the synergy of Mo active site and Vo in the catalyst significantly boosted the activation kinetics of PMS. Evidently, the Mo site of different oxidation states contributed to chemical activation of PMS, while the Vo favored the activation of PMS and the generation of non-radical 1O2 species. As a result, the Mo/MoO2-10 h/PMS system delivered a complete removal of acid orange 7 (AO7) within 4 min, significantly exceeding the activity of Mo/PMS (16%), MoO2-H/PMS (25%) and most of other PMS-based systems. Moreover, the current system showed high potential for removal of different pollutants including antibiotics and organic dyes. Radical quenching experiments and electron paramagnetic resonance (EPR) studies revealed that the 1O2 species was significant for AO7 decomposition. This work provided a novel strategy to a batch-scale synthesis of high-performance PMS activator for water remediation in practice. [Display omitted] •A facile electro-explosive route to synthesize the oxygen vacancy enriched Mo/MoO2 catalyst of high yield.•Mo site of varied oxidation states plus oxygen vacancy favor PMS activation and critical 1O2 species formation.•Full degradation of AO7 with a rate constant of 1.108 min−1 achieved on the Mo/MoO2-10h/PMS system.•Mechanism of PMS activation, AO7 degradation, and toxicity prediction of intermediates discussed in detail.•The current system also highly potential for removal of other pollutants including CIP, TC, RhB, and MB.