Electron Hopping Process in SWCNT-Mediated Redox Reaction: An Evidence Observed by DFT Theory

摘要

The electron hopping mechanism in SWCNT-mediated redox reaction of anthraquinonnyl (AQH_2-) and 4-arylhydroxyl amine (4AHA-) groups is systematically studied by DFT for the first time. It was found that electrons from the oxidized AQH_2 group can transfer to the oxidizing 4AHA group at the other end of the nanotube by the hopping process through the mediating SWCNT confirmed by the non-localized distribution of the hopping electrons. The electron density and Hirshfeld partial charges analysis shows that SWCNT can hold 87% of the extra electron density of the hypothetical negative intermediate forming by the oxidation of the AQH_2 process. Chemical attachments of these two redox reagents to the SWCNT also caused new impurity states within the band gap, thereby introducing more metallic characteristics to the system. These findings provide a detailed understanding of the electron hopping process and agree well with the previous experimental study.