Atomic coordination engineering for overcoming the selectivity-durability tradeoff of carbon-encapsulated metals towards sustainable wastewater purification

Breaking the selectivity-durability tradeoff of carbon-encapsulated cobalt/peroxymonosulfate (C-Co/PMS) remains challenging. Although singlet oxygen ( 1 O 2 ) derived from C-Co/PMS shows high selectivity toward electron-rich pollutants, it is readily quenched by water, which impairs catalytic durability during repeated operation. Herein, we rationally construct copper single atoms on C-Co (Cu SA -C-Co) to trigger the formation of additional high-valent copper-oxo species (Cu(III)-OH) during PMS activation, which compensates for the intrinsic defect of sole 1 O 2 , overcoming this critical tradeoff. On Co sites, adsorbed PMS undergoes O-H dissociation to form peroxomonosulfate radical (*SO 5 •- ), which self-disproportionates into 1 O 2 . Meanwhile, strong orbital hybridization between the Cu 3 d orbital of Cu SA and the O 2 p orbitals of PMS induces heterolytic cleavage of peroxide O-O bonds, facilitating oxygen atom transfer to generate Cu(III)-OH. Benefiting from these complementary oxidation pathways, Cu SA -C-Co/PMS retains high selectivity toward electron-rich pollutants while achieving catalytic durability during repeated cycling compared with pristine C-Co/PMS. Beyond the sole 1 O 2 -mediated mineralization of bisphenol A (BPA), Cu(III)-OH converts BPA into oligomers via proton-coupled electron transfer, and these oligomers spontaneously accumulate on the Cu SA -C-Co surface, which simplifies subsequent water treatment. Continuous treatment of BPA-containing wastewater over 240 h shows that the Cu SA -C-Co/polyvinylidene fluoride/PMS system sustains > 91.4% BPA removal.