Acetone Sensing Performance of Pristine and Gold Doped Graphene Sheet: A Comparative Analysis

The present work investigates the improved acetone sensing performance of gold (Au)-decorated graphene sheet over pristine graphene sheet via first principles based computational method using the Gaussian 09W and Gauss View 6.0 packages. Acetone was taken as the adsorbed gas/vapor for both pristine graphene and Au-decorated graphene leading to the formation of acetone-adsorbed pristine graphene sheet (Type-I system), and acetone-adsorbed Au-doped graphene sheet (Type-II system). The interaction between them was explored through the calculation of various electronic characteristics like HOMO (the highest occupied molecular orbital), LUMO (the lowest unoccupied molecular orbital), molecular electrostatic potential (MEP), density of states (DOS), band structure, and Mulliken charge analysis. Semi-metallic nature of the system was confirmed from the calculated band structure. It was found that graphene sheet showed better reactivity, when doped with Au atom resulting in strong adsorption energy (-0.801 eV), and improved binding distance (2.34 Å). Our results suggested that introducing foreign Au atoms in pristine graphene sheet leads to improved sensitivity towards acetone vapor owing to the catalytic activity of Au atoms along with the larger surface area, and faster transport kinetics of graphene sheet.