Facile synthesis of N-doped carbon nanorods for antibiotics degradation via PMS activation: Mechanism insight and biotoxicity assessment

Abstract

Free radical based-advanced oxidation processes are often seriously affected by background inorganic anions in the actual wastewater treatment, limiting their practical use in complex water substrates. In order to solve this problem, herein, we first reported N-doped carbon nanorods (NCNs) as the high-efficiency catalysts, by pyrolysis of pullulan and dopamine hydrochloride, for water decontamination via non-radical pathway. The detailed characterizations exhibited that NCN-550 presented a structure of nanorod-shaped, with graphitic C/N, C=O, COOH and C-OH, which were favor of selective 1O2 formation via PMS activation. The control experiments, EPR analysis and DFT calculation confirmed graphitic N and C=O groups of NCN-550 played the significant roles in PMS activation, with promoting the catalytic mechanism switched from SO4•- based-AOPs to non-radical oxidative pathways (1O2 and electron transfer) in antibiotics degradation. The NCN-550/PMS system possesses a superior anti-disturbance performance for common anions on antibiotics degradation in complex water substrates. In addition, seed germination experiments confirmed the biotoxicity of tetracycline (TC) to wheat seeds was greatly reduced after degradation by NCN-550/PMS system.