ABSTRACT Functionalized exfoliated graphene oxide (EGO) for supercapacitor electrodes have been synthesized by simple chemical methods from the exfoliated graphite (EG) as precursor. Structural and morphological characterizations of EGO have been carried out using X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), FTIR and Raman spectroscopy. Electrochemical performance of these electrodes has been investigated using cyclic voltammetry, galvanostatic charge-discharge, and electrochemical impedance spectroscopy. The fabricated supercapacitor gave a specific capacitance of 146 Fg-1 and energy density of 20 Wh·kg-1 for a highly oxidized sample with more functional groups compared to pure, lower level oxidized and reduced samples. The single and multi layered graphene oxide sheets produced by this method have a lower degree of agglomeration. We found that the graphene oxide with functional oxygen groups of quinine type enhances the capacitance compared to other oxygen functional groups.
Cite this paper
P. Karthika, N. Rajalakshmi and K. Dhathathreyan, "Functionalized Exfoliated Graphene Oxide as Supercapacitor Electrodes," Soft Nanoscience Letters, Vol. 2 No. 4, 2012, pp. 59-66. doi: 10.4236/snl.2012.24011.
 B. E. Conway, “Electrochemical Supercapacitors: Scientific Fundamentals and Technological Applications,” Kluwer Academic/Plenum Publishers, New York, 1999.
 R. Kotz and M. Carlen, “Principles and Applications of Electrochemical Capacitors,” Electrochimica Acta, Vol. 45, No. 15-16, 2000, pp. 2483-2498.
 A. Burke, “Ultracapacitors: Why, How, and Where Is the Technology,” Journal of Power Sources, Vol. 91, No. 1, 2000, pp. 37-50. doi:10.1016/S0378-7753(00)00485-7
 “Basic Research Needs for Electrical Energy Storage: Report of the Basic Energy Sciences Workshop on Electrical Energy Storage, 2-4 April 2007,” Office of Basic Energy Sciences, Department of Energy, July 2007.
 J. Schindall, “The Charge of the Ultracapacitors,” IEEE Spectrum, Vol. 44, No. 11, 2007, pp. 42-46.
 S. Stankovich, D. A. Dikin, G. H. B. Dommett, K. M. Kohlhaas, E. J. Zimney, E. A. Stach, R. D. Piner, S. T. Nguyen and R. S. Ruoff, “Graphene-Based Composite Materials,” Nature, Vol. 442, No. 7100, 2006, pp. 282286. doi:10.1038/nature04969
 D. A. Dikin, S. Stankovich, E. J. Zimney, R. D. Piner, G. H. B. Dommett, G. Evmenenko, S. T. Nguyen and R. S. Ruoff, “Preparation and Characterization of Graphene Oxide Paper,” Nature, Vol. 448, No. 7152, 2007, pp. 457460. doi:10.1038/nature06016
 J. S. Bunch, A. M. van der Zande, S. S. Verbridge, I. W Frank, D. M. Tanenbaum, J. M. Parpia, H. G. Craighead and P. L. McEuen, “Electromechanical Resonators from Graphene Sheets,” Science, Vol. 315, No. 58, 2007, pp. 490-493. doi:10.1126/science.1136836
 S. Watcharotone, D. A. Dikin, S. Stankovich, R. Piner, I. Jung, G. H. B. Dommett, G. Evmenenko, S. E. Wu, S. F. Chen, C. P. Liu, S. T. Nguyen and R. S. Ruoff, “Graphene-Silica Composite Thin Films as Transparent Conductors,” Nano Letters, Vol. 7, No. 7, 2007, pp. 18881892. doi:10.1021/nl070477+
 C. Gomez-Navarro, R. T. Weitz, A. M. Bittner, M. Scolari, A. Mews, M. Burghard and K. Kern, “Electronic Transport Properties of Individual Chemically Reduced Graphene Oxide Sheets,” Nano Letters, Vol. 7, No. 11, 2007, pp. 3499-3503. doi:10.1021/nl072090c
 F. Schedin, A. K. Geim, S. V. Morozov, E. W. Hill, P. Blake, M. I. Katsnelson and K. S. Novoselov, “Detection of Individual Gas Molecules Adsorbed on Graphene,” Nature Materials, Vol. 6, No. 9, 2007, pp. 652-655.
 A. A. Balandin, S. Ghosh, W. Z. Bao, I. Calizo, D. Teweldebrhan, F. Miao and C. N. Lau, “Superior Thermal Conductivity of Single-Layer Graphene,” Nano Letters, Vol. 8, No. 3, 2008, pp. 902-907. doi:10.1021/nl0731872
 C. Gomez-Navarro, M. Burghard and K. Kern, “Elastic Properties of Chemically Derived Single Graphene Sheets,” Nano Letters, Vol. 8, No. 7, 2008, pp. 2045-2049.
 X. Wang, L. J. Zhi and K. Mullen, “Transparent, Conductive Graphene Electrodes for Dye-Sensitized Solar Cells,” Nano Letters, Vol. 8, No. 1, 2008, pp. 323-327.
 D. Li, M. B. Muller, S. Gilje, R. B. Kaner and G. G. Wallace, “Processable Aqueous Dispersions of Graphene Nanosheets,” Nature Nanotechnology, Vol. 3, No. 2, 2008, pp. 101-105. doi:10.1038/nnano.2007.451
 S. R. C. Vivekchand, C. S. Rout, K. S. Subrahmanyam, A. Govindaraj and C. N. R. J. Rao, “Graphene-Based Electrochemical Supercapacitors,” Chemistry and Materials Science, Vol. 120, No. 1, 2008, pp. 9-13.
 K. S. Subrahmanyam, S. R. C. Vivekchand, A. Govindaraj and C. N. R. Rao, “A Study of Graphenes Prepared by Different Methods: Characterization, Properties and Solubilization,” Journal of Materials Chemistry, Vol. 18, No. 13, 2008, pp. 1517-1523.
 S. M. Paek, E. Yoo and I. Honma, “Enhanced Cyclic Performance and Lithium Storage Capacity of SnO2/Graphene Nanoporous Electrodes with Three-Dimensionally Delaminated Flexible Structure,” Nano Letters, Vol. 9, No. 1, 2009, pp. 72-75. doi:10.1021/nl802484w
 S. D. Meryl, P. Sungjin, Z. Yanwu, A. Jinho and R. S. Rodney, “Graphene-Based Ultracapacitors,” Nano Letters, Vol. 8, No. 10, 2008, pp. 3498-33502.
 T. Ramanathan, A. A. Abdala, S. Stankovich, D. A. Dikin, M. Herrera-Alonso, R. D. Piner, D. H. Adamson, H. C. Schniepp, X. Chen, R. S. Ruoff, S. T. Nguyen, I. A. Aksay, R. K. Prudhomme and L. C. Brinson, “Functionalized Graphene Sheets for Polymer Nanocomposites,” Nature Nanotechnology, Vol. 3, No. 6, 2008, pp. 327-331.
 E. Yoo, J. Kim, E. Hosono, H. Zhou, T. Kudo and I. Honma, “Large Reversible Li Storage of Graphene Nanosheet Families for Use in Rechargeable Lithium Ion Batteries,” Nano Letters, Vol. 8, No. 8, 2008, pp. 2277-2282.
 M. D. Stoller, S. J. Park, Y. W. Zhu, J. H. An and R. S. Ruoff, “Graphene-Based Ultracapacitors,” Nano Letters, Vol. 8, No. 10, 2008, pp. 3498-3502.
 D.-W. Wang, F. Li, J. P. Zhao, W. C. Ren, Z.-G. Chen, J. Tan, Z.-S. Wu, I. Gentle, G. Q. Lu and H.-M. Cheng, “Fabrication of Graphene/Polyaniline Composite Paper via in Situ Anodic Electropolymerization for High-Performance Flexible Electrode,” ACS Nano, Vol. 3, No. 7, 2009, pp. 1745-1752. doi:10.1021/nn900297m
 J. Yan, T. Wei, Z. J. Fan, W. Z. Qian, M. L. Zhang, X. D. Shen and F. Wei, “Preparation of Graphene Nanosheet/Carbon Nanotube/Polyaniline Composite as Electrode Material for Supercapacitors,” Journal of Power Sources, Vol. 195, No. 9, 2009, pp. 3041-3045.
 M. Kaempgen, K. Candace, J. Chan, Y.C. Ma and G. Gruner, “Printable Thin Film Supercapacitors Using Single-Walled Carbon Nanotubes,” Nanoletters, Vol. 9, No. 5, 2009, pp. 1872-1876. doi:10.1021/nl8038579
 W. S. Hummers Jr. and R. E. Offeman, “Preparation of Graphitic Oxide,” Journal of the American Chemical Society, Vol. 80, No. 6, 1958, p. 1339.
 D. Hulicova, J. Yamashita, Y. Soneda, H. Hatori and M. Kodama, “Supercapacitors Prepared from MelamineBased Carbon,” Chemistry Materials, Vol. 17, No. 5, 2005, pp. 1241-1247. doi:10.1021/cm049337g
 D. Hulicova, M. Kodama and H. Hatori, “Electrochemical Performance of Nitrogen-Enriched Carbons in Aqueous and Non-Aqueous Supercapacitors,” Chemistry Materials, Vol. 18, No. 9, 2006, pp. 2318-2326.
 G. Lota, B. Grzyb, H. Machnikowska, J. Machnikowski and E. Frackowiak, “Effect of Nitrogen in Carbon Electrode on the Supercapacitor Performance,” Chemical Physics Letters, Vol. 404, No. 1-3, 2005, pp. 53-58.
 G. Lota, K. Lota and E. Frackowiak, “Nanotubes Based Composites Rich in Nitrogen for Supercapacitor Application,” Electrochemistry Communications, Vol. 9, No. 7, 2007, pp. 1828-1832. doi:10.1016/j.elecom.2007.04.015