Activation of peroxydisulfate degradation of ciprofloxacin by nitrogen-doped modified graphitized iron-based carbon materials: The transition from free to nonfree radicals

Considering that high concentrations of ciprofloxacin (CIP) are generally ecotoxic and persistent in water bodies, the refractory degradability has not been addressed in depth. In this study, an N-doped modified graphitized iron-based carbon nanomaterial (0.8 N@FeCS) was prepared by hydrothermal synthesis for the rapid degradation of ciprofloxacin by activated peroxydisulfate. More importantly, the N-doped nitrogen configuration in the iron-based carbon material is pyridine nitrogen, pyrrole nitrogen and graphite nitrogen. The nitrogen modification imparts a new twist to the CIP degradation system: a shift from a common free radical reaction to a nonradical process (1O2 and electron transfer pathways). The degradation intermediates were identified by LC-MS analysis and density functional theory (DFT), it is suggested that the possible CIP degradation pathway. In conclusion, the process of catalytic activation results in removal of CIP, and this study provides a new perspective for the removal of antibiotics from aqueous solutions.