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Periodate (PI) has recently been studied as an excellent oxidant in advanced oxidation processes, and its reported mechanism is mainly the formation of reactive oxygen species (ROS). This work presents an efficient approach using N-doped iron-based porous carbon (Fe@N-C) to activate periodate for the degradation of sulfisoxazole (SIZ). Characterization results indicated the catalyst has high catalytic activity, stable structure, and high electron transfer activity. In terms of degradation mechanism, it is pointed out that the non-radical pathway is the dominant mechanism. In order to prove this mechanism, we have carried out scavenging experiments, electron paramagnetic resonance (EPR) analysis, salt bridge experiments and electrochemical experiments, which demonstrate the occurrence of mediated electron transfer mechanism. Fe@N-C could mediate the electron transfer from organic contaminant molecules to PI, thus improving the efficiency of PI utilization, rather than simply inducing the activation of PI through Fe@N-C. The overall results of this study provided a new understanding into the application of Fe@N-C activated PI in wastewater treatment. [Display omitted] • The activation of PI was successfully promoted with Fe@N-C. • The reaction mechanism of Fe@N-C/PI system is electron transfer mechanism. • The degradation pathway of pollutants in Fe@N-C/PI system was proposed. • No iodate and other harmful byproducts were produced during the reaction. [ABSTRACT FROM AUTHOR]

In this study, N and O co-doping carbon materials with porous structure (NOPC-x) were applied to activate peroxymonosulfate (PMS) for bisphenol (BPA) degradation and the underlying effects in affecting NOPC-x activity were revealed. Electrochemical characterization, electron paramagnetic resonance (EPR) tests, quenching and PMS adsorption experiments were applied to clarify the mechanism of BPA degradation. It's found that BPA can be completely removed within 20 min (k obs = 0.30 min−1) in the NOPC/PMS system depending on the electron transfer path with the necessity of moderate surfaced unpaired electrons for electrons delivery, which could be regulated by the modifier dosage. However, excessive surfaced unpaired electrons were unfavorable to PMS adsorption, resulting in deterioration of BPA degradation. This study indicates that controlling the amount of surfaced unpaired electrons in an appropriate range is essential to ensure the carbonaceous materials activity in PMS activation to obtain a satisfactory BPA degradation. [Display omitted] ● NOPC exhibited superior activity for BPA degradation by PMS activation. ● Increasing heteroatomic doping enhanced the amount of surfaced unpaired electrons. ● Degradation of BPA was proposed to follow a nonradical electron transfer pathway. ● The role of surfaced unpaired electrons of NOPC in PMS activation was clarified. [ABSTRACT FROM AUTHOR]