  Graphene nanoplatelets (GnPs) are promising candidates for gas sensing
applications because they have a high surface area to volume ratio, high
conductivity, and a high temperature stability. Also, they cost less to
synthesize, and they are lightweight, making them even more attractive than
other 2D carbon-based materials. In this paper, the surface and structural
properties of pristine and functionalized GnPs, specifically with carboxyl,
ammonia, carboxyl, nitrogen, oxygen, fluorocarbon, and argon, were examined
with Raman spectroscopy, Fourier transform infrared spectroscopy, X-ray
photoelectron spectroscopy and X-ray diffraction (XRD) to determine the
functional groups present and effects of those groups on the structural and
vibrational properties. We attribute certain features in the observed Raman
spectra to the variations in concentration of the functionalized GnPs. XRD
results show smaller crystallite sizes for functionalized GnPs samples that
agree with images acquired with scanning electron microscopy. Lastly, a
molecular dynamics simulation is employed to gain a better understanding of the
Raman and adsorption properties of pristine GnPs.
