Nitrogen and phosphorus co-doped carbon materials co-catalyzed Fenton chemistry for long-lasting water decontamination

The sluggish reaction kinetics between H₂O₂ and Fe(III) significantly limit the practical application of the Fenton process. Although nitrogen-doped carbon materials (C N) can promote electron transfer and facilitate Fe(III) reduction, further enhancement of Fe(III)/Fe(II) redox cycling remains challenging. Herein, we propose a synergistic phosphorus and nitrogen co-doping strategy to overcome this limitation. By optimizing surface electronic structure and porous characteristics, the prepared nitrogen and phosphorus co-doped carbon (CN–P) markedly improved the reduction efficiency of Fe(III). Phosphorus incorporation modulates charge distribution, enhances electron transport capability, and increases the redox activity of surface Fe(III), thereby accelerating H₂O₂-induced Fe(III) reduction. The optimized CN–P–4 catalyst exhibited a pseudo-first-order rate constant ( k obs ) of 0.51 min −1 , which is 2.68 times higher than that of C N (0.19 min −1 ), demonstrating effective acceleration of the rate-determining step in the Fe(III)/Fe(II) cycle. Spectroscopic and electrochemical analyses confirm that the enhanced performance originates primarily from electronic structure regulation rather than surface area effects. Despite possessing only moderate specific surface area with predominant meso /macroporous features, CN–P achieved efficient pollutant degradation through enhanced hydroxyl radical (•OH) generation. Mechanistic studies reveal that highly active surface Fe(III) species can be readily reduced by H₂O₂ without external energy input, initiating a self-sustained Fenton chain reaction. This work provides mechanistic insight and a rational design strategy for developing efficient and sustainable Fenton co-catalysts.