Facile synthesis of graphene sheets from fluorinated graphite

One of the problems with the chemical exfoliation of graphite to graphene via oxidation and reduction, is the excessive oxidation of graphite and incomplete reduction of graphene oxide, which introduce many defects and unnecessary oxygen-containing groups into the graphene sheets. Therefore, it is difficult to create high quality graphene sheets with few defects on a large scale by chemical exfoliation. Here, a simple and convenient method is developed to prepare graphene with a little fluorine by ultrasonicating fluorinated graphite in hydrazine hydrate. For comparison, reduced graphene oxide (RGO) was also prepared by Hummers method. The results showed that thin and flat graphene prepared from fluorinated graphite has a monocrystalline structure, while RGO presents turbostratic stacking. Moreover, the thermal stability and electrical conductivity of the as-prepared graphene sheets (GS) are much higher than those of the RGO sheets.