Syntheses and Characterizations of Functionalized Graphenes and Reduced Graphene Oxide

Graphene oxide (GO) was prepared by the Hummers and Offeman method from graphite. Reduced graphene oxide (RGO) and functionalized graphenes were synthesized from GO by using hydrazine hydrate and amine-functionalized alkyl groups, respectively. The structures of the G. RGO, and functionalized graphenes were identified by FTIR and C-13 NMR. In addition, we examined the thermal stability, morphology, and dispersibility of the materials in various organic solvents. AFM disclosed that GO and RGO consisted of one- or two-layer graphene regions throughout the film. However, the functionalized graphene films showed average thicknesses of 2.26 similar to 3.30 urn. The thermal stability of the functionalized graphenes was poorer than that of the RGO. The functionalized graphenes were well dispersed in toluene or chloroform, as evidenced by the lack of the characteristic graphite reflection in the solutions.