▎ 摘　　要

Large area (similar to cm(2)) multi-layer graphene film is synthesized in the substrate-free vapor phase. The scanning electron microscopy observation reveals that the graphene nanoflakes are either six- or five-sided, and the internal angles between adjacent sides are nearly 120 degrees and 105 degrees, respectively. The nucleation of hexagonal and pentagonal carbon rings leads to carbonaceous nuclei, which grow into six- or five-sided nanoflakes, respectively. A well-ordered and large-area graphene monolayer is formed by the interconnection of these flakes, and stacking of these monolayers results in the formation of a multi-layer graphene film. The creation of hexagonal and pentagonal carbon rings is considered to be important for the easy production of large area multi-layer graphene at large scale. (C) 2010 Elsevier Ltd. All rights reserved.