Directional electron transfer in single-atom cobalt nanozyme for enhanced photo-Fenton-like reaction

In this study, enzyme-mimicking single-atom (EMSA) catalyst was fabricated by implanting cobalamin cofactor-resembling Co-N4 sites into graphite carbon nitride (g-C3N4). The EMSA-Co sites inherit the high catalytic ac-tivity and selectivity from natural enzymes and demonstrate outstanding performance for persulfate (PS) acti-vation under visible light (Vis). The kinetic rate constant for BPA degradation in the EMSA-Co-g-C3N4 +PS+Vis system was about 33 times faster than that in the g-C3N4+PS+Vis system. The benefits of high reactivity and selectivity of the EMSA-Co sites led to efficient generation of the radical species (SO4 & BULL;, & BULL;OH and O2 & BULL;-), resulting in the fast elimination of various organic pollutants. Mechanisms studies reveal that the directional ultrafast electron transfer in the EMSA-Co nanozyme leads to an accelerated redox circulation of the Co single sites, thereby boosting their performance for photo-Fenton-like reaction. This study opens up the avenue of robust and efficient enzyme-like SACs for applications in environmental remediation.

Automated summary

In this research, enzyme-mimicking single-atom catalyst was created by incorporating Co-N4 sites into graphite carbon nitride. The catalytic activity and selectivity of the EMSA-Co sites were similar to natural enzymes, and they showed excellent performance in activating persulfate under visible light. The EMSA-Co-g-C3N4 + PS + Vis system exhibited a BPA degradation rate 33 times faster than the g-C3N4 + PS + Vis system. The high reactivity and selectivity of EMSA-Co sites led to efficient generation of radical species, resulting in the rapid elimination of various organic pollutants. Mechanistic studies showed that the directional ultrafast electron transfer in EMSA-Co nanozyme accelerated the redox circulation of Co single sites, enhancing their performance in photo-Fenton-like reactions. This study opens up new possibilities for the use of robust and efficient enzyme-like single-atom catalysts in environmental remediation.