Synthesis of OMS-2/graphite nanocomposites with enhanced activity for pollutants degradation in the presence of peroxymonosulfate.

The octahedral molecular sieve manganese oxide (OMS-2) and graphite (Gt) composites (OMS-2/Gt) were prepared by a facile refluxing approach. The structure and morphology of the obtained materials were systematically investigated. The results reveal that OMS-2 nanofibers are uniformly dispersed on the surface of Gt, and the ratio of Mn 3+ species in OMS-2 increases lineally with the increase of Gt dosage. The catalytic activity of OMS-2/Gt was evaluated by the degradation of Acid Orange 7 (AO7) in the presence of peroxymonosulfate (PMS). It is found that the OMS-2/Gt composites show enhanced catalytic performance with the degradation rate lineally correlated with the content of OMS-2 in the catalyst, and even with the ratio of Mn 3+ /Mn 4+ . XPS and radical scavenger experiments further indicated that the oxidation of Mn 3+ by PMS system occurs in the system with the formation of hydroxyl radicals contributed to the dye degradation . The catalysts also exhibit good stability and reusability during consecutive cycles. Thus, the environmental friendly OMS-2/Gt composites with low cost, facile synthesis process and high efficiency are very promising catalysts for PMS activation and pollutants degradation.