Reduced Fe, Mn-based catalyst with dual reaction sites for rapid decolorization treatment via Fenton-like reactions

Abstract

Ferromanganese oxides are promising efficient catalysts for peroxymonosulfate (PMS) activation. In this study, a novel porous ferromanganese oxides (FeMnOx) nanocubes derived from prussian blue analogues was prepared via a successive codeposition-calcination method, and the reduced Fe, Mn-based catalysts were further synthesized by a hydrogenation process. Their catalytic performance was evaluated in a Fenton-like degradation of Rhodamine B (RhB) and other dyes in the presence of PMS. It was found that FeMnOx showed outstanding catalytic activity in dyes elimination, which benefited by the synergetic effect of dual reaction sites, reductive Fe-Mn binary oxides and oxygen vacancies (OVs) for PMS activation. The optimized sample (H2 annealed at 260 °C, FMO-260) exhibited high degradation efficiency to RhB within 5 cycles and after regeneration, implying the strong stability and reusability. Moreover, the influences of PMS and FMO-260 dosages, pH values, coexist anions for the degradation efficiency to RhB were also carried out. According to inhibitor experiments and EPR (electron paramagnetic resonance) tests, a possible catalytic mechanism and degradation pathway of RhB was proposed. This study provides a novel fabrication strategy to design Fe, Mn-based catalysts and demonstrates more potential in the decolorization field.