Single-atom Co-N3 sites induce peroxymonosulfate activation for acetaminophen degradation via nearly 100 % internal electron transfer process

A non-radical persulfate oxidation system activated by biochar-supported single-Co-atom catalyst (CoNBC600) was explored in this work. The experimental data and density functional theory calculations showed the Co atom coordinated with three N atoms was the primary active site for peroxymonosulfate (PMS) activation, resulting in the formation of surface-bonded active complexes (CoNBC600-PMS*) and high-valent metal oxides. Acetaminophen (APAP) was completely degraded within 11 min through a nearly 100 % internal electron transfer process between CoNBC600-PMS* and APAP, with an outstanding specific rate constant of 15.33 min −1 g −2 L 2 . The CoNBC600/PMS system exhibited high selective degradation toward organic pollutants that have low half-wave potential and high levels of the highest occupied molecular orbital. The polyvinylidene fluoride supported CoNBC600 membrane sustained steady PMS activation in a continuous flow-through system. This work provides a comprehensive understanding of the activation process of PMS by the CoNBC600 and offers a pathway to developing practical Fenton-like systems for wastewater remediation.