Surface-bound reactive oxygen species dominated catalytic ozonation for decontamination via CuO-Co3O4 heterostructure

A novel surface oxidation-dominated heterogeneous catalytic ozonation (HCO) process was developed to overcome matrix-induced scavenging limitations. By fabricating CuO-Co 3 O 4 heterojunction as catalyst, surface adsorbed hydroxyl radical (•OH ad ) and surface atomic oxygen ( ⁎ O ad ) emerge as primary reactive oxygen species (ROS) from ozone decomposition. The engineered catalyst achieves 4.3-fold and 1.9-fold higher oxalic acid degradation efficiency than CuO and Co 3 O 4 , respectively, accompanied by broad-spectrum mineralization for refractory pollutants and robust Cl⁻ resistance with verification in actual hypersaline industrial wastewater treatment. Combined characterization and theoretical calculations reveal that heterojunction formation increases Lewis acid sites and induces directional electron transfer from CuO to Co 3 O 4 , thereby lowering ozone activation barriers and accelerating surface-bound ROS generation, wherein O 3 is preferentially decomposed into •OH ad and ⁎ O ad at Co sites but only •OH ad at Cu sites. Collectively, this study advances a surface-bound ROS mediated catalytic ozonation paradigm with superior matrix resistance, enabling broader industrial deployment of HCO.