Chemisorption of hydrogen-molecule on axially strained (8, 0) carbon nanotube

The axial strain is shown to have effective influence on the behaviors of hydrogen chemisorption/desorption on the (8, 0) carbon nanotube by density functional simulations. For the chemisorption/desorption pathway with lowest energy barrier in our work, a compressive strain of ∼7% can lower the energy barrier of the chemisorption (desorption) from 1.98 (1.64) eV to 1.56 (1.20) eV, while the tensile strain increases the energy barrier but makes the chemisorption configuration (C1C4) become more stable compared to the corresponding physisorption configuration. The hydrogen adsorption and release of the most stable chemisorption state (C2C3) are based on the transition between the C2C3 and C1C4 configurations. However, the influence of the axial strain on the hydrogen diffusion behavior which controls die transition between C2C3 and C1C4 configurations is found to be weak.