Zigzag “N-C-C-S” Engineering Enables Nitrogen Configuration Reconstruction in Dual-Atom Doped Carbons for Boosted Fenton-like Oxidation and Dynamic Reaction Mechanism Regulation

Graphitic nitrogen (N) is the optimal N configuration for peroxymonosulfate (PMS) activation, yet its formation is poorly controllable and usually scarce in N-doped carbon catalysts. Herein, a novel zigzag “N-C-C-S” engineering strategy via sulfur (S)-assisted doping is developed to fabricate S, N co-doped porous carbons (S x N-PCs). Precise tuning of S/N ratio induces N configuration reconstruction, increasing graphitic N content. S 0.57 N-PC affords a 3.1-fold enhancement in PMS activation activity, completely removing bisphenol A (BPA) with a high reaction rate constant (0.597   min -1 ). The “N-C-C-S” moiety enables dynamic switching of reaction mechanisms from radical-initiated degradation to 1 O 2 -mediated mineralization via tailored electronic states of graphitic N. Characterizations and theoretical calculations reveal that S atoms can occupy carbon matrix defects, triggering electron redistribution between adjacent N and C atoms to lower the energy barrier for graphitic N formation. Furthermore, the “N-C-C-S” moiety forms an electron-delocalized system that modulates graphitic N to a moderately electron-enriched state, preserving HSO 5 - adsorption capacity while reducing the energy barrier of PMS decomposition. This optimized electronic state of graphitic N stabilizes active O* intermediates and reduces their formation energy barrier, thereby promoting 1 O 2 generation. A continuous-flow system using S 0.57 N-PC@PVDF membrane demonstrates exceptional durability over 36   h in real-world wastewater treatment.