Activation of periodate by N-doped iron-based porous carbon for degradation of sulfisoxazole: Significance of catalyst-mediated electron transfer mechanism

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 under-standing into the application of Fe@N-C activated PI in wastewater treatment.

Automated summary

This study demonstrated the efficient degradation of sulfisoxazole (SIZ) using N-doped iron-based porous carbon (Fe@N-C) as a catalyst to activate periodate (PI). The Fe@N-C catalyst exhibited high catalytic activity, stable structure, and excellent electron transfer activity. The non-radical pathway was identified as the dominant degradation mechanism, which was supported by scavenging experiments, electron paramagnetic resonance (EPR) analysis, salt bridge experiments, and electrochemical experiments. Fe@N-C mediated the electron transfer from organic contaminant molecules to PI, improving the efficiency of PI utilization. This study provides new insights into the application of Fe@N-C activated PI in wastewater treatment.