▎ 摘　　要

A few-layer graphene was obtained by the expansion and exfoliation of water-intercalated graphene oxide via heat treatment in nitrogen environment in the temperature range of 200-1000 degrees C. Graphene which was synthesized at 800 degrees C (GT800) had a higher quality than other temperatures. This graphene has a high specific surface area (560.6 m(2) g(-1)) and nano-porous structure. However, as for the purpose of comparison, graphene was synthesized with a colloidal suspension of exfoliated graphene oxide sheets in water with hydrazine hydrate in various reaction times (12, 24 and 36 h). This method has obtained a six-layer graphene and graphene that was synthesized during 24 h reaction with hydrazine hydrate (GC24) had a higher quality in comparison with the other products. The GC24 had 195.97 m(2) g(-1) specific surface area and nano-porous structure. The as-synthesized graphene were then characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, Raman spectroscopy, transmission electron microscopy (TEM), scanning electron microscopy (SEM) as well as BET measurements. The results demonstrated that this low-cost method for few-layer grapheme, e.g. three-layers, fabrication is reliable and promising. (C) 2013 Elsevier B.V. All rights reserved.