Micro-mechanism of multi-pathway activation peroxymonosulfate by copper-doped cobalt silicate: The dual role of copper

Abstract

Bimetallic catalysts tend to show excellent catalytic performance to activate peroxymonosulfate (PMS) due to the synergistic effect. Although the outstanding catalytic ability of metal silicates to activate PMS has been clarified for a long time, the synergistic effect and micro-mechanism of bimetal in silicate are still being ignored. In this work, we prepared Cu-doped cobalt silicate (CuCoSi) hollow nanospheres to confirm the synergistic effect of bimetal in silicate for activating PMS. A novel and comprehensive synergistic micro-mechanism at the molecular and electronic levels is proposed. Experimental and theoretical analysis reveals that Co provides unique active sites in CuCoSi and Cu enhances the radical pathway by electron transfer with Co instead of directly participating in the activation of PMS. The increased oxygen vacancies (Ov) in the material promotes the formation of 1O2 due to Cu doping. This work lays a foundation of the development of bimetallic silicates catalysts.