Cobalt-Zinc carbonaceous yolk-shell reactor enhances electron transfer in non-radical pathways: Electric potential concentration effect via bimetallic synergy.

Abstract

Bimetallic catalysts have notable advantages in the field of persulfate activation owing to their intermetallic synergy. However, studies on stimulating the potential concentration effect through intermetallic coordination to enhance the electron transfer efficiency are limited. In this study, a cobalt (Co) and zinc (Zn) bimetallic yolk-shell structured high-efficiency peroxymonosulfate (PMS) catalyst (Z67@8-HCNF) was prepared by the derivatization of metal-organic backbone materials and was found to produce significant synergistic interactions between Co and Zn metals, which could be utilized to trigger the potential concentration effect to enhance the intermolecular electron transfer efficiency and achieve efficient PMS activation. Experimental and theoretical calculations showed that a Co and Zn bimetallic neighborhood coordination configuration (Co-Zn-N@C) was constructed through the synergistic interaction of Zn and Co, which synchronously enhanced the electric field strengths at the Co and Zn metal centers, thereby inducing a potential concentration and a significant increase in the Co and Zn potentials. This potential concentration effect enhances PMS adsorption and electron transfer, promoting the catalytic degradation performance. In this study, we propose a mechanism to enhance the catalytic degradation efficiency of the non-radical pathway through the potential concentration effect of the simultaneous enhancement of the Co and Zn bi-substituent potentials, which provides new inspiration for the continued development of highly efficient bimetallic catalysts to improve water purification technology in complex environments.