Iron and nitrogen co-doped porous carbon derived from natural cellulose of wood activating peroxymonosulfate for degradation of tetracycline: Role of delignification and mechanisms

Iron and nitrogen co-doped porous carbon materials as peroxymonosulfate (PMS) activator for tetracycline (TC) degradation were prepared by pyrolyzing the mixture of iron loading cellulose and melamine under N2 flow. The cellulose obtained from balsawood through delignification with sodium chlorite. The delignification of wood obviously improved the specific surface area and enhanced the catalytic efficiency of carbon materials obtained after pyrolysis. Enhancing graphitization degree of carbon material demonstrated that delignification of wood was conducive to formation of a short-range ordered graphitic structure during pyrolysis, which facilitated to the improvement of adsorption/catalytic performance of the carbon materials. The prepared catalyst exhibited excellent catalytic stability and adaptability under the conditions of different systems. Radical quenching test and electron paramagnetic resonance measurements suggested that superoxide radical (O2·-) and singlet oxygen (1O2) played dominant roles in TC degradation. Fe0/Fe3C, pyridine N and graphite N were the dominant active sites for PMS activation. This research provides new insights for the development of biomass derived high performance carbon catalysts and their application in wastewater treatment via PMS based advanced oxidation processes.