Nitrogen-doped carbon material encapsulated Fe3C with dual-reaction centres to boost peroxymonosulfate activation for efficient organic pollutant removal

Peroxymonosulfate (PMS) activation based on iron-based catalyst has caught increasing attention in wastewater treatment, but is strongly impeded by the sluggish kinetics of Fe(II) recovery. In this study, nitrogen-doped carbon encapsulated Fe3C with dual-reaction centres coupled via C-Fe channel was developed by electro-spinning and Chemical Vapor Deposition (CVD) technique. The remarkable catalysis performance was conferred by the formation of C-Fe short bond which linked C poor electron reaction centres from N-doped carbon frameworks and the Fe rich electron reaction centres from Fe3C. Fe@NC-800 achieved 100% sulfamethoxazole (SMX) degradation within 20 min, and showed excellent cycle stability after 5 cycles. The electron transfer rate between the dual-reaction region was accelerated due to short transport distance and low transmission resis-tance. Electrons from pollutants were compensated to Fe3+ via C-Fe bond bridges, promoting the regeneration of Fe2+ and accelerating the efficiency of the Fe2+/Fe3+ cycle. Besides, the experiments of reactive oxygen species (ROS) quenching and capture revealed the degradation pathway. Both radical and nonradical oxidation played a key role in the Fe@NC-800/PMS system. This work will offer a valuable clue on the design of multi -benefit catalysts to achieve efficient removal of pollutants in wastewater.