In the process of pollutant degradation by activating peroxymonosulfate (PMS) with carbon-based Fenton-like catalysts containing Fe as the active site, the influence of Zn atoms on the system has rarely been studied. In this study, by regulating the introduction of Zn sources, Fe-Zn-C and Fe-C catalysts were successfully synthesized for activating PMS to degrade butyl xanthate (BX). The degradation experiment results showed that compared to the Fe-C system, the doping of Zn increased the degradation rate of BX in the Fe-Zn-C system by 10.66%, reaching 91.19% within 120 min. Moreover, by optimizing the reaction conditions, the highest BX degradation efficiency of 96.54% was achieved within 30 min. Through instrumental analysis, Fe and Zn elements were found to exist on the surface of the catalysts in the form of Fe2+Fe3+2O4 and ZnO crystals, and the catalytic oxidation reaction was dominated by non-free radical pathways, including 1O2 and direct electron transfer pathways. No free radicals were produced during the reaction, and it was speculated that Zn atoms played the role of an electron bridge in the reaction system, mediating electron transfer and enhancing catalytic performance through their synergistic effect with Fe. Comprehensive stability evaluation indicated that Fe-Zn-C ensures continuous catalytic activity and ecological safety with a low dissolution rate in aqueous solution. This study provides a new approach for the design of Fenton-like catalysts and the induction of non-radical pathways.
Huang et al. (Thu,) studied this question.