Chemisorption of Hydrogen Atoms on the Sidewalls of Armchair Single-Walled Carbon Nanotubes

Abstract

A computational study using the B3LYP/6-31G(d) level of theory shows that the chemisorptions of one and two hydrogen atoms on the external surface of (3,3), (4,4), (5,5), and (6,6) armchair single-walled carbon nanotubes (SWNTs) are exothermic processes. Our results clearly indicate that two hydrogen atoms favor binding at adjacent positions rather than at alternate carbon sites. This is different from the results reported on zigzag nanotubes (Yang et al. J. Phys. Chem. B 2006, 110, 6236). In general, the exothermicity of hydrogen chemisorption decreases as the diameter of the armchair nanotubes increases, which is in contrast to the observation for zigzag-type structures. The chemisorptions of one and two hydrogen atoms significantly alter the C−C bond lengths of the nanotube in the vicinity of hydrogen addition as a result of a change in hybridization of the carbon atom(s) at the chemisorption site(s) from sp2 to sp3. The effect of increasing the length of the SWNTs on the geometries and the reaction energies of hydrogen chemisorption has also been explored.

Cumulative π‐π interaction triggers unusually high stabilization of linear hydrocarbons inside the single‐walled carbon nanotube

“…CNTs can be used in nanoelectronic and biocompatible devices, nanocomposite materials, as catalysts and molecular sensors [5][6][7][8][9][10][11][12]. Typically, the physicochemical properties of CNTs are strongly influenced by surface modification that opens up interesting opportunities in the chemistry of single-walled carbon nanotubes (SWNTs) [2,[13][14][15][16][17][18][19]. Similar to fullerene case [20], the insertion of atoms or molecules or ions inside single-and multi-walled CNTs allows one to modify the tube properties for specific applications [21][22][23][24][25][26][27][28][29].…”

Estudo teórico de propriedades ópticas não-lineares de nanotubos de carbono de parede única quimicamente modificados

“…Os átomos de carbono participantes das ligações com os substituintes (C2 e C7, Figura 4), antes com hibridização sp 2 , passam a ter características de carbono sp 3 , como pode ser observado através da média dos comprimentos das ligações C-C (=1,53 Å) e ângulos ), consistente com a alta simetria do sistema (D 5h ). Ambos os métodos mostraram-se destoantes do ponto de vista quantitativo, apresentando, de forma geral, tendências equivalentes.…”

Theoretical Study of Chemisorption of Hydrogen and Fluorine Atoms on the Sidewalls Armchair Single-walled Carbon Nanotubes with Two Carbon Ad-dimer Defects

“…SWCNTs are considered as promising hydrogen storage media. Chemisorption of hydrogen atoms on the exterior surface of defect-free SWCNTs has been extensively investigated [12,13]. In the paper, the structural and electronic properties of armchair with two carbon ad-dimer defect and the chemisorption of hydrogen and fluorine on the surface of these nanotubes were studied through density functional theory method.…”