ElectronTransfer Expressway from Peroxydisulfateto O₂ Mediated by Diatomic Sites Accelerating ¹O₂ Production for Disinfection

Current studies on high-density single-atom catalysts (SACs) with the coexistence of single atomic and diatomic sites have ignored the underlying contribution of diatomic sites for persulfate-based disinfection technology. Herein, high-density atomic Ni anchored on <i>N</i>-doped carbon (Ni₁–NC) containing abundant Ni diatomic (Ni₂–N₆) sites, was fabricated, exhibiting superior peroxydisulfate (PDS) activation to generate singlet oxygen (¹O₂) for disinfection compared with other M₁–NC, due to the fact that Ni₁–NC possessed the highest negative crystal orbital Hamilton population value. A dynamic promotion effect toward disinfection, relying on the level of external O₂ was discovered. This promotion effect was achieved through the cooperation of PDS and O₂ which was mediated by Ni₂–N₆ sites bridging electron transfer from PDS to O₂, thereby suppressing the energy barriers of rate-determining steps. Disinfection with decreased horizontal gene transfer was achieved by disrupting coenzyme Q, inhibiting adenosine triphosphate synthesis, and degrading extracellular polymeric substances via ¹O₂. A continuous flow system based on a Ni₁–NC@sponge fixed reaction bed displayed persistent disinfection for 336 h under aeration. This work presents a transboundary integrated PDS disinfection strategy combining physical aeration and chemical oxidation through tailoring diatomic sites in SACs.