Cobalt Oxide Nanoclusters on N-Doped Carbon Black Enable Direct Electron Transfer for Efficient Peroxymonosulfate Activation

Advanced oxidation processes (AOPs) leveraging peroxymonosulfate (PMS) activation are pivotal for water remediation, yet conventional catalysts face trade-offs between metal leaching and inertness. Here, we report a cobalt oxide-anchored nitrogen-doped carbon black (CoOx-NCB) catalyst. Through a scalable one-step pyrolysis strategy, CoOx-NCB achieves ultralow cobalt leaching (<0.1 ppm) while exhibiting exceptional PMS activation efficiency, degrading 100% phenol within 30 min. Mechanistic studies reveal that nitrogen doping induces charge redistribution, forming electron-deficient CoOx clusters that directly mediate electron transfer from pollutants to PMS via a surface-bound PMS* complex, bypassing radical pathways. The catalyst demonstrates broad applicability across 14 phenolic contaminants and resists interference from common inorganic ions. This work establishes a paradigm for designing scalable, stable, and low-metal-content nanocluster catalysts with the dual advantages of high reactivity and environmental safety.