The adsorption of hydrogen and fluorine atoms on the interior surfaces of defect-free and Stone-Wales defect armchair (5,5) single-walled carbon nanotubes were investigated using density functional theory. The reaction energy values for the hydrogenation and fluorination at all of the possible unique sites were obtained at the UB3LYP/6-31G* level. The calculated reaction energy values were used to corroborate the reactivities of different sites on the interior surfaces of single-walled carbon nanotubes. The results indicated that, for defect-free nanotubes, endohedral adsorption was rather unfavorable for both hydrogen and fluorine. The computed exothermal values ranged from 4.8 to 13.4kcal/mol for hydrogenation and from 16.6 to 23.2kcal/mol for fluorination. However, the introduction of a Stone-Wales defect on the (5,5) single-walled carbon nanotube improved the chemical reactivity of the interior surface of the defected tube. The computed exothermal values for the endohedral hydrogen and fluorine atoms were within the ranges of 7.0 to 33.4 and 18.5 to 41.8kcal/mol, respectively. The most exothermic and reactive site on the interior surface of Stone-Wales defective (5,5) single-walled carbon nanotubes was the C2 site shared by two seven-membered rings and one five-membered ring. This was different from reported results on the reactivity of the exterior surfaces of Stone-Wales defective nanotubes. The electronic and vibrational properties of the (5,5) single-walled carbon nanotubes with adsorption of hydrogen and fluorine atoms on the interior surface were also explored.

Reactivity of the Interior Surface of (5,5) Single-Walled Carbon Nanotubes with and without a Stone-Wales Defect. X.Wang, K.Wang, Q.Meng, D.Wang: Computational and Theoretical Chemistry, 2014, 1027, 160-4