A theoretical study on surface reactivity of fluorinated (n,0) and (n,n) carbon nanotubes (n = 3-6)

Density functional theory calculations are performed to investigate the surface reactivity of pristine as well as fluorine-terminated zigzag (n,0) and armchair (n,n) carbon nanotubes (n = 3-6). The properties determined include the electrostatic potential V(r) and average local ionization energy Ī(r) on the surfaces of the investigated tubes. A general feature of all of the systems studied is that stronger potentials are associated with regions of higher curvature. The results indicate that both V(r) and Ī(r) detect the effects of fluorine-terminated regions in which significant effects are observed for those atoms in the vicinity of the fluorine-terminated regions. Comparison with the Ī(r) of the pristine nanotube indicates correctly that in the fluorine-terminated models, the fluorine atoms tend to deactivate the surface toward electrophilic/radical attack. (author)