Spectroscopy and Molecular Dynamics Simulation of Graphene Nanoplatelets for Sensitive Gas Sensing

Graphene Nanoplatelets (GnPs) hold promise of being effective gas sensors because of their high surface-to-volume ratio, lightweight and superior conductivity. Pristine and GnPs specifically functionalized with carboxyl, ammonia, nitrogen, oxygen, fluorocarbon and oxygen have been characterized using a variety of spectroscopic techniques, including Raman, FT-IR and X-ray diffraction (XRD), along with Molecular Dynamics simulation and COMSOL Multiphysics modeling. XRD measurements show smaller crystallite sizes for carboxyl-functionalized GnPs as compared to pristine, which has been confirmed using Scanning Electron Microscopy. Modeling and simulations showed that the resistance of a GnP-based gas sensor decreased on exposure to nitrogen dioxide, whereas an opposite trend and enhanced sensitivity was observed for carbon monoxide exposure.