Program

O.1 -- Oral, NCTP-40

Date: Monday, 27 July 2015

Time: 11h00 - 11h20

Density functional studies of gas molecules adsorbed on Graphene Nanoribbons

Nguyen Tien Cuong and Nguyen Manh Tien

Faculty of Physics, VNU University of Science, Hanoi, Vietnam

We present first-principles studies on adsorption of CO2 and NH3 gas molecules on pristine and modified graphene nanoribbons (GNRs). Electronic properties and transport properties are calculated using density functional theory and non-equilibrium Green’s function method, respectively. Adsorption energy, density of states, and charge transfer are examined.It is found that both CO2 and NH3 molecules show physical adsorption on pristine GNRs with low adsorption energies and small charge transfer. In contract, the adsorptions of the molecules on modified GNRs are chemical adsorption. The analysis of electron density deformation and charge transfer demonstrate that NH3 and CO2 adsorbed on GNRs exhibit donor-like and acceptor-like behavior, respectively. We also calculated transmission spectra and current-voltage characteristics for the GNRs with and without adsorption of gas molecules. The obtained results suggest that the sensitivity and selectivity of designed GNR-based gas sensors could be significantly improved by introducing the modified electronic structures of the GNR systems

Presenter: Nguyen Tien Cuong