Electrochemical Characterization of Graphite Oxide and Graphene Electrodes

It is of great interest to look for facile synthetic approaches of graphene nanosheet (GNs) due to its unusual characteristics. However, reported previously involved long process time and high synthetic temperature [1-4]. To improve mentioned above, the present work provided a rapid, energy conservation and non-hazardous preparation of chemically converted GNs. In this study, microwave irradiation was implemented as heating source to reduce the reaction time to tens minutes and ethylene glycol (EG) was introduced as a reducing agent successfully instead of toxic hydrazine [3-5] while reduction process of graphite oxide (GO) prepared by Hummer’s method [6]. Introduction Graphene, a spotlighted material applied in nanoelectronic devices, based on its unique honeycomb structure and excellent mechanical and electronic properties [7-9]. The remarkable properties of graphene reported so far include high values of its Young’s modulus (~1,100 GPa) [10], fracture strength (125 GPa) [10], thermal conductivity (~5,000 W m K ) [11], mobility of charge carriers (200,000 cm V s) [12] and specific surface area (calculated value, 2,630 m g ) [13]. Results and Discussion Figure 1 displays the X-ray diffraction (XRD) patterns of nature graphite (NG) as precursors, GO, and GNs, respectively. The d002 of nature graphite was 3.34 A which dramatically shifted to 7.30 A after oxidation process indicated the insertion of hydroxyl and epoxy groups were taken place between the carbon layers of graphite [5]. After EG reduction process, the significant displacement of d002 was occurred again from 7.30 A to 3.95 A revealed the formation of the exfoliated GNs. In addition, the broad diffraction peak of GNs (002) implied the poor ordering along the direction which was built up from single or fewer layers of GNs. Figure 2 shows the transmission electron microscopy (TEM) image of reduced GNs with transparent nature exhibited fewer layers stacking after EG reduction process. In summary, the investigations above display a convenient and nontoxic chemical route to obtain the GNs. 10 20 30 2 theta (degree) Graphene Nano-sheets 10 20 30