A core-shell Mn–C@Fe nanocatalyst under ozone activation for efficient organic degradation: Surface-mediated non-radical oxidation

A non-radical catalytic ozonation process functionalized by Mn(II)-sites was found effective to degrade oxalic acid as a typical refractory compound that is hard to remove through catalytic ozonation with hydroxyl radical oxidation. Specifically, we prepared functional Mn–C@Fe nanoparticles with carbon shell supporting Mn 3 O 4 for catalysis while encapsulating magnetic iron core for recycle. Batch study shows its excellent catalytic reactivity on the degradation of organics particular for the ozone-recalcitrant oxalic acid (20 min for 90.9% removal, kinetics constant of 0.045 min −1 ). Our mechanism study ruled out the hydroxyl radical oxidation, and highlighted the formation of a heptavalent Mn intermediate oxidant responsible for the fast degradation that was initiated via ozone activation of Mn(II)-sites on the carbon shell. Our findings underscore a non-radical catalytic ozonation as a promising alternative technology for the abatement of aqueous organic pollutants.