External electric field induced oxygen-driven unzipping of carbon nanotubes

Based on density functional theory, the mechanisms for oxygen-driven unzipping of carbon nanotubes under electric field are presented. Under the control of external electric field, O adatoms will diffuse along the single-walled carbon nanotube from low potential to the high potential sites. The energy barrier of O adatoms diffusion gets lower while increasing the electric potential, thus enabling the O adatoms to diffuse to the higher potential sites more easily. And with quantities of O adatoms diffusing to the high potential sites, a linear epoxy chain is formed and the single-walled carbon nanotube will be unzipped into graphene nanoribbons automatically.