Advanced mineralization of refractory contaminants by synergistic Cu(III)-O and ¹O₂ in doubly charged oxygen...

The synergistic system integrating ¹O₂-driven hydroxylation with Cu(III)-O-mediated single-electron transfer oxidation is expected to achieve efficient mineralization of contaminant. The targeted construction of the Cu(III)-O and ¹O₂ synergistic system is promising but limited by *SO₅^•- formation and two-electron reaction barriers. Doubly charged oxygen vacancy (V_o²⁺) is expected to address these limitations by reducing the electron density at Cu sites. Herein, a ZIF-8 sacrificial template strategy was proposed to in-situ construct CuO-modified ZnO with V_o²⁺ for peroxymonosulfate (PMS) activation. Linear regression analysis showed a positive correlation between the degradation rate constant and V_o²⁺ intensity (Pearson's coefficient = 0.99, p = 0.01). V_o²⁺ lowered the Cu-site electron density and reduced the O-O cleavage energy barrier in Cu(Ⅱ)-OOSO₃, promoting the co-generation of Cu(III)-O and ¹O₂, and the concentration of ¹O₂ increased by 34.3 folds after the intensity of V_o²⁺ was enhanced by 2.4 folds. The synergistic system achieved efficient mineralization via ¹O₂-initiated hydroxylation and Cu(III)-O-mediated single-electron transfer oxidation of intermediates. This work provided a synergistic Fenton-like oxidation strategy for efficient refractory contaminants mineralization.