Initiating nonradical-dominated persulfate activation by N doping on Co3O4 enables efficient organic pollutant degradation

Low-cost and efficient catalysts are decisive for the broadened implementation of advanced oxidation processes (AOPs) in wastewater remediation. Based on the modified hypothesis by inducing a nonradical pathway, we designed the N-doped Co3O4 (N-Co3O4) for peroxydisulfate (PDS) activation by facile post-treatment of Co3O4 with N precursor at low temperature. The N-Co3O4/PDS system exhibited excellent degradation efficiency (98.7 %) in 1 h for the removal of typical organic pollutant (acid organic 7), enhanced by 41.4 % compared to Co3O4/ PDS. Remarkably, distinguish from sluggish degradation by Co3O4, N-Co3O4 achieved an enhanced kinetic process with the degradation efficiency of 97.7 % in 5 min, making it outstanding to save time and economic costs. We discovered the activation mechanism by N-Co3O4 covered the nonradical pathways of singlet oxygen (O-1(2)) and electron transfer, overcoming the sole radical pathway of Co3O4. The emerging oxygen vacancies on N-Co(3)O(4)boosted the generation of active O-1(2) with .O-2(-) intermediates, and benefited the electron transfer process with lower resistance. N doping introduced Co-N basic sites facilitated the PDS adsorption, improving the electron transfer capability. This study proposes a facile protocol to convert transition metal oxide to functional catalyst and demonstrates the immense potential to create nonradical dominated degradation.

Automated summary

This article investigated the application of a low-cost and efficient catalyst in wastewater treatment. By modifying Co3O4 with N precursor, N-doped Co3O4 (N-Co3O4) was synthesized. Compared to Co3O4, N-Co3O4 exhibited higher degradation efficiency in a shorter period of time, and the activation mechanism involving nonradical pathways was proposed.