Curved interface-induced Jahn-Teller effect in single-atom catalysts for water purification

Single-atom catalysts (SACs)-based advanced oxidation processes (AOPs) are an ideal green and efficient water purification technology, but intrinsic mechanisms and interface effects pose significant challenges. Herein, we have achieved precise Jahn-Teller (J-T) effect control of atomic metal-N₄-C (M-N₄-C: M = Mn, Fe, Co, and Ni) to boost the AOPs, showing a volcano-fit-like behavior. Theoretical calculation and experiments reveal the adsorption of O-O of peroxymonosulfate on the M-N₄-C site, leading to the local C plane bending and inducing the intensity of the J-T effect of Mn, Fe and Co, weakening the d-p orbital hybridization ability with *HSO₄ intermediates for reducing the energy barrier for reactive oxygen species production. Importantly, the long-term activity of 100 h in a 20 L flow reactor indicates promising practical wastewater treatment on an industrial scale. This work presents a perspective on the rational design of tuning the metal d orbital in SACs for sustainable environmental remediation.