Tuning nitrogen microenvironments in biomass-derived cobalt catalysts enables non-radical PMS activation for selective pollutant degradations

Cotton-derived Co-CN-X catalysts via dopamine-assisted polymerization–pyrolysis. • Co-CN-24 exhibits superior catalytic activity and robust stability in PMS activation. • Nitrogen doping catalysts coupled PMS system governs non-radical pathways toward electron-rich pollutants degradation. Biomass-derived materials offer renewability and waste valorization for water purification, yet identifying and controlling their precise ROS-driven degradation pathway in peroxymonosulfate (PMS)-based systems remains a fundamental challenge. Herein, we report N-doped cobalt‑carbon catalysts (Co-CN-X) from cotton via polymerization-pyrolysis and show how nitrogen doping tailors PMS activation for pollutant degradation. Upon nitrogen introduction, the optimized Co-CN-24 catalyst achieves efficient carbamazepine degradation, reaching 96.55% within 35 min with a 7.12-fold enhancement in reaction efficiency compared to the Co-C counterpart. Integrated characterization and DFT calculations reveal that Co-CN-24 possessing high pyrrolic N and Co 0 content abundant facilitates 1 O 2 generation, thereby increasing the dominance of non-radical pathways in pollutant degradation. Most importantly, the Co-CN-24/PMS system exhibits selective reactivity toward electron-rich pollutants, broad pH tolerance, and robust performance in complex water matrices, including continuous flow experiments. This work provides mechanistic insight into how nitrogen doping regulates non-radical pathways in biomass-derived catalysts, offering a sustainable strategy for targeted pollutant remediation.