One-step growth of vertical graphene sheets on carbon nanotubes and their field emission properties

Graphene-carbon nanotube hybrid is prepared by an in situ growth of vertical graphene sheets on carbon nanotubes (CNTs), using one-step plasma-enhanced chemical vapor deposition, without catalyst. TEM analysis indicates that the growth of graphene is in accordance with the defects of carbon nanotubes introduced by high-energy ion bombardment in microwave plasma and expands by epitaxial growth. The results suggest that the method is ideal for preparing uniform graphene-carbon nanotube hybrid and demonstrate a categorical explanation for the growth mechanism of graphene-CNTs hybrid. Because of its uniform networks and multistage structure, the graphene-CNTs hybrid exhibits good field emission properties. (C) 2013 AIP Publishing LLC.