Electron Transfer Expressway from Peroxydisulfate to O2 Mediated by Diatomic Sites Accelerating 1O2 Production for Disinfection.

Abstract

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 N-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.