Effects of the topological and chemical modification on the electronic properties of graphene

Graphene as a fundamental building block for carbon materials has attracted great attention over the last decade because of its novel properties. The peculiar electronic properties of graphene intrinsically originate from the geometry of its honeycomb lattice. In addition, the pure two-dimensional structure, where all carbon atoms lie in the surface, gives graphene extreme sensitivity to the influence of external chemical species, where the electronic properties are easily tuned through chemical modification. In this review, the electronic properties of graphene are discussed in terms of the influence of the topological and chemical modification. This promises to be a promising strategy to understand the fundamental properties of carbon materials in various forms.