While Co is the most effective metal for activating PMS, extensive efforts are made to develop Co/Fe species (CF) (e.g., CoFe2O4) for imparting magnetic properties and facilitating recovery of catalysts. When carbon substrates are doped with heteroatoms (e.g., S and N) and CF is embedded within the heteroatom-doped carbon matrix, synergies can occur to boost catalytic activities. This study proposes an alternative CF-bearing carbonaceous composite, a cobalt-containing Prussian Blue Analogue (PBA) (Co3[Fe(CN)6]2) is employed as a precursor for preparing CF species embedded in N-doped carbon matrix and immobilized on S/N-co-doped carbon (SNC). Specifically, PBA in-situ grows on SNC by a heat treatment of trithiocyanuric acid to form PBA@SNC, which is then carbonized into CF species@SNC (CF@SNC). By adopting Amaranth degradation as a model reaction, CF@SNC shows a higher catalytic activity (kapp = 0.230 min-1) than CF (kapp = 0.152 min-1) and SNC (kapp = 0.016 min-1) for activating PMS. In comparison with Co3O4, CF@SNC exhibits a higher catalytic activity for PMS activation. CF@SNC renders a relatively low Ea value (53 kJ/mol) for Amaranth degradation in comparison to other reported catalysts. These comparisons demonstrate the advantageous features of CF@SNC as a magnetic and efficient catalyst for PMS activation.
Keywords: Advanced oxidation; Cobalt-iron catalysts; Metal-carbon composites; Sulfate radicals; Sulfur-nitrogen doping.
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