▎ 摘　　要

Junctions are the key component for 3D CNT-graphene seamless hybrid nanostructures attractive for numerous innovative applications. Growth mechanism of junctions of vertical carbon nanotubes (CNTs) growing from graphene in the presence of iron nanoparticles as catalysts was simulated using quantum mechanical molecular dynamics methods. When nanotube grew on graphene via a "base-growth" mechanism, it was found that the junctions were a mixture of C C and Fe C covalent bonds. We further explored the formation mechanisms of pure C C bonded junctions by moving the catalyst during CNT growth or etching and annealing after growth. Our simulations provided possible avenues to produce pure C C bonded junctions that seamlessly connect graphene and nanotubes in the 3D nanostructures. (C) 2013 Elsevier Ltd. All rights reserved.