Regulating Co-O covalency in CuCoO₂ via asymmetric 3d-2p-3d configuration enhances peracetic acid activation for water decontamination

Nowadays, the creation of effective catalysts and the profound comprehension of their interfacial mechanisms in the heterogeneous catalytic oxidation processes remain substantial challenges. This work focused on the covalency regulation of the Co-O bond via the configuration of the asymmetric 3d-2p-3d hybridized orbital within the Co-O-Mn structure, inducing an electron rearrangement from Mn(III) to Co(III). This enabled efficient PAA activation with 94.9% removal of 2,4,6-TCP at a rate constant of 0.151 min⁻¹. Upon electronic modulation, the energy difference between Co 3d and O 2p decreased from 0.66 eV to 0.13 eV, strengthening PAA adsorption (ΔE_ads = −7.03 eV vs. -0.36 eV for pure CuCoO₂). Meanwhile, the regulation of the Co-O bond covalency lowered the electrical resistance of the catalyst, which enhanced the interfacial electron transfer during PAA activation and facilitated the generation of CH₃C(O)OO•, thereby enabling efficient degradation of the organic pollutants. The presence of Cu(I) species facilitated the reduction of Co(III) and Mn(IV), overcoming the obstacle of catalyst poisoning. This work provides novel insights into fully understanding the intrinsic mechanisms of PAA activation and benefits the design of durable catalysts.