Integrating bimetallic nanoclusters onto a porous g-C₃N₄ support for efficient degradation of metronidazole: Performance and mechanism study

Preparing catalysts for efficient degradation of antibiotics is an important and challenging objective across various fields, from water treatment to public health. In this study, we developed CoMnO_x/g-C₃N₄ hybrid catalysts by integrating CoMnO_x bimetallic oxides onto a 3D porous g-C₃N₄ support via activated peroxymonosulfate (PMS), which achieved high degradation efficiency for metronidazole (99.8 %), as well as pollutants such as methyl orange (99.4 %), ofloxacin (97.0 %), tetracycline (86.8 %), and oxytetracycline (84.7 %). The joint experimental and theoretical findings demonstrate that the CoMnO_x nanoclusters integrated in the catalyst significantly enhance the adsorption and activation of PMS, thanks to the synergistic effects of the Co and Mn sites. Therefore, we propose a non-free radical catalytic mechanism that relies on ¹O₂ as the primary active species, where radicals such as SO₄∙^-, ∙OH, and O₂∙^- primarily contribute to the formation of ¹O₂. We suggest that our work provides a model for clarifying the critical roles played by cooperative bimetallic nanoclusters in PMS activation for efficient antibiotic degradation, and also paves the way for new opportunities in designing and controlling chemical compounds for water treatment.