| AVS 55th International Symposium & Exhibition | |
| Graphene Topical Conference | Monday Sessions |
| Session GR+TF+NC-MoM |
| Session: | Graphene and 2-D Carbon Nanostructures |
| Presenter: | R.A. Quinlan, College of William and Mary |
| Authors: | R.A. Quinlan, College of William and Mary E. Widenkvist, Uppsala U., Sweden J. Groff, College of William and Mary M. Rooth, Uppsala U., Sweden M. Kelly, Stanford U. R.A. Outlaw, College of William and Mary V. Coleman, Uppsala U., Sweden O. Karis, Uppsala U., Sweden B. Sanyal, Uppsala U., Sweden O. Eriksson, Uppsala U., Sweden H. Grennberg, Uppsala U., Sweden B.C. Holloway, Luna Innovations, Inc. U. Jansson, Uppsala U., Sweden |
| Correspondent: | Click to Email |
Carbon nanosheets (CNSs) are novel free-standing carbon nanostructures, composed of horizontal basal planes and vertical sheets which are made up of 1-7 graphene layers.1 Previous work described the successful creation of defects in the graphene lattice via an acid-treatment and the characterization of these defects with x-ray absorption near-edge spectroscopy (XANES). The presence of a peak in the carbon K-edge spectra at 287eV was assigned to a C-O σ* resonance. Theoretical modeling of a di-vacancy in a graphene bilayer system reproduced the spectra and predicts metallic conductivity of the states surrounding the defect.2 Here we report the further characterization of functionalized carbon nanosheets (f-CNSs) via high resolution x-ray photoelectron spectroscopy (XPS) and thermal desorption spectroscopy (TDS). Measurements were made at room temperature up to 700K with as-deposited, water- and acid-treated CNSs. XPS measurements indicate an increase in the oxygen content of the nanostructures from 1-2% in as-deposited up to 3-4% in the acid-treated samples. The decrease of sub-peak areas in the C1s and O1s spectra with heating correlates well with the decrease in atomic oxygen content. The partial pressures of H2, O2, CO2, CO and H2O measured desorbing from the f-CNSs support the model of oxygen and hydrogen decorated defects in the graphene system. The XPS and TDS results support XANES measurements of similar samples. These results support the use of a non-oxidizing acid-treatment for controlled defect formation in a graphene system, a first step towards the development of graphene based devices.
1 Wang et al., Free-standing subnanometer graphite sheets. Applied Physics Letters, 2004. 85(7): p. 1265-1267
2 Coleman et al., Defect formation in graphene nanosheets by acid treatment: an x-ray absorption spectroscopy and density functional theory study. Journal of Physics D: Applied Physics, 2008(6): p. 062001.