Influence of High Atomic Hydrogenation on the Electronic Structure of Zigzag Carbon Nanotubes: A First-Principles Study

Using density functional theory, we study high hydrogenated zigzag single-walled carbon nanotubes from (7,0) to (11,0). Two structure transitions are classified: type A is a metallic transition and type B is a "semiconductive transition'' according to the energy band structure. The charge density transforms only at the C-C bonds without hydrogenated sites. The sp³ hybridization is mainly enhanced for all the C-C bonds in the vertical axial direction for type-A configurations, and the sp³ hybridization mainly increases for all C-C bonds along the axial direction for the type-B case.