Cobalt single-atom catalysts (Co-SAs) are rising stars
in persulfate
chemistry for their well-defined coordination, reduced metal usage,
and exceptional activity. However, the simultaneous formation of cobalt
nanoparticles (Co-NPs) with Co-SAs raises questions about their complex
interplay and synergy in catalysis. In this study, we synthesized
Co-SAs-encapsulated Co-NPs (CoNP@NC/Co-SA) using the laser-induced
carbonization strategy of high entropy synthesis technology. The results
show that 93.23% of phenol can be removed in 15 min and 91.60% in
3 min in the CoNP@NC/Co-SA/PMS system. Simulation results showed that
Co-NPs fine-tune the electronic structure of Co-SA sites, optimizing
PMS adsorption and activation to generate confined reactive species.
The surface-activated PMS-catalyst complex directly attacked adsorbed
pollutants on the catalyst surface via an electron-transfer regime.
CoNP@NC/Co-SA catalyzes PMS oxidation through a nonradical pathway
with high selectivity toward target organics. The findings emphasize
the synergistic effect of Co-SAs and Co-NPs in promoting Fenton-like
catalysis, enlightening the rational design of advanced composite
materials via synergistic molecular and interfacial engineering for
fast and long-lasting catalytic oxidation. At the same time, this
work provides insights into the electronic structure regulation of
metal centers at the atomic level.