Cation-pi structure inducing efficient peroxymonosulfate activation for pollutant degradation over atomically dispersed cobalt bonding graphene-like nanospheres

Orbital interaction involving metal cation-pi is an important form for electron transfer regulation. To accelerate the interfacial electron transfer of peroxymonosulfate (PMS) activation for water treatment, we report a new strategy through bonding atomically dispersed cobalt with nanospheric C-based graphene-like structures (SACo-NGs) to form metal cation-pi structure, driving rapid and directional transfer of the electrons of pollutants to PMS on the catalyst surface. The catalyst SACo-NGs is synthesized by an enhanced hydrothermal-sintering method and the formation of metal cation-pi structure is demonstrated by X-ray absorption fine structure (EXAFS), X-ray photoelectron spectroscopy (XPS), electron paramagnetic resonance spectroscopy (EPR) and Raman spectroscopy. It is found that CO-pi structures (Co2+-N-C-pi) play a key role for the efficient activation of PMS, which results in pollutants being greatly removed in a few minutes. During the reaction, pollutants can donate electrons for the system through pi-pi interaction accompanying by the direct oxidative degradation of pollutants. The obtained electrons are quickly transferred to the atomically dispersed cobalt sites through the formed cation-pi structure, which promotes the activation of PMS. This is a successful practice in the field of PMS activation using cation-pi structure to accelerate electron transfer and achieve rapid degradation of pollutants.

Automated summary

In this study, a new strategy was developed to accelerate electron transfer and achieve rapid degradation of pollutants by forming metal cation-pi structure through bonding atomically dispersed cobalt with nanospheric C-based graphene-like structures. The CO-pi structures were found to play a key role in the efficient activation of PMS, leading to rapid removal of pollutants. The successful practice demonstrated the potential of using cation-pi structure to enhance PMS activation and pollutant degradation.