Hierarchical porous graphite-like carbon nanosheet cooperated with Fe/Fe3C@Fe-N-C nanocomposites toward catalytic oxidation process

In this work, Fe, N co-doped hierarchical porous graphite-like carbon with carbon-encapsulated Fe/Fe 3 C@ Fe-N-C was synthesized by a facile solid-phase synthesis strategy, and was employed as an efficient catalyst to activate peroxymonosulfate (PMS) for oxidation of tetracycline (TC). The optimal Fe-N/C 800 outlined a highly catalytic performance in activating peroxymonosulfate (PMS) with TC decomposition rate reaching 89.2 % in 20 min at ultra-low catalyst dosage. Meanwhile, the effect of operating parameters was also investigated in order to evaluate the potential of using Fe-N/C 800 in practical applications. In addition, the characterization analysis and experiments results elucidated that graphitic N, pyridinic N, C O, Fe 3 C, Fe 0 and FeN 4 were considered as the main reactive species promoting the PMS activation to generate reactive oxygen species (ROS) (including singlet oxygen ( 1 O 2 ), sulfate radical (SO 4 •- ) and hydroxyl radical (•OH)). The electron paramagnetic resonance (EPR) experiments and radicals quenching analyses further demonstrated that the non-radical species singlet oxygen ( 1 O 2 ) was the dominant reactive oxygen species. Moreover, the TC degradation pathways were presented by LC-MS. Ultimately, the toxicity of the intermediate products were also investigated by ECOSAR system.