Controlled synthesis of few-layered graphene sheets on a large scale using chemical exfoliation

The synthesis of few-layered graphene sheets with controlled number of layers (3-4) on a large scale was developed using chemical exfoliation by simply controlling the oxidation and exfoliation procedure. The obtained Few-layered Graphene Oxide (FGO) was characterized by atomic force microscopy, X-ray diffraction, thermal gravimetric analysis and Ultraviolet-visible spectroscopy. It is found that the FGO, which contains less functional groups than single-layered graphene oxide (GO), also has excellent water dispersion. Moreover, after reduction treatments under the same conditions as that used for GO, reduced FGO show a much better electrical conductivity of 108 S/cm, two-orders higher than reduced GO. (C) 2010 Elsevier Ltd. All rights reserved.