Synthesis of Graphene with Microwave Irradiation in Liquid Phase

Graphite oxide was synthesized with Hummers method using natural flake graphite as carbon source, and then graphene was prepared through microwave irradiation in N-methyl-2-pyrrolidinone (NMP) solvent. NMP solvent was heated selectively during the microwave irradiation process, meantime, the oxygen containing groups of graphite oxide were decomposed into CO, CO2 and H2O gases, resulting in the exfoliation and reduction of graphite oxide. XRD, SEM, EDS, TEM, HRTEM, SAED, XPS and Raman were performed to characterize the synthesized graphene. The results indicate that the synthesized graphene is transparent with several microns in size, which consists of 2–5 graphitic layers with high crystalline structure. The synthesized graphene can disperse homogenously in the NMP solvent.