Cobalt single-atom/cluster synergy for precision water decontamination: Unlocking a nearly 100 % electron-transfer...

Precisely modulating electronic and coordination structures of Fenton-like catalysts to achieve electron transfer pathway (ETP)-dominated oxidation remains challenging. Herein, a CoN₃/Co_NP hybrid catalyst was constructed for the effective activation of peroxymonosulfate (PMS), which mediated primarily through a dominant electron transfer process (ETP). Notably, CoN₃/Co_NP/PMS achieved ultra-rapid and complete degradation of phenol (20 mg/L within 3 min) with an ultralow catalyst dosage (20 mg/L), leading to efficient detoxification and a 72.4 % mineralization rate through ETP-driven polymerization and hydroxylation. Mechanism studies confirmed an inner-sphere ETP process with high selectivity toward electron-rich organics and strong anti-interference capability over a wide pH range. DFT calculations further revealed that Co nanoclusters remarkably enhanced electron density and upshift the d-band center, thereby together strengthening PMS adsorption and facilitating electron transfer. This work offers a new approach to designing synergistic single-atom/cluster catalysts for highly selective pollutant degradation.