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Detection of hydrogen using graphene.

Ehemann RC, Krstić PS, Dadras J, Kent PR, Jakowski J - Nanoscale Res Lett (2012)

Bottom Line: Irradiation dynamics of a single graphene sheet bombarded by hydrogen atoms is studied in the incident energy range of 0.1 to 200 eV.Results for reflection, transmission, and adsorption probabilities, as well as effects of a single adsorbed atom to the electronic properties of graphene, are obtained by the quantum-classical Monte Carlo molecular dynamics within a self-consistent-charge-density functional tight binding formalism We compare these results with those, distinctly different, obtained by the classical molecular dynamics.PACS: 61.80.Az, 61.48.Gh, 61.80.Jh, 34.50.Dy.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Physics and Astronomy, Middle Tennessee State University, Murfreesboro, TN, 37130, USA. rce2g@mtmail.mtsu.edu.

ABSTRACT
Irradiation dynamics of a single graphene sheet bombarded by hydrogen atoms is studied in the incident energy range of 0.1 to 200 eV. Results for reflection, transmission, and adsorption probabilities, as well as effects of a single adsorbed atom to the electronic properties of graphene, are obtained by the quantum-classical Monte Carlo molecular dynamics within a self-consistent-charge-density functional tight binding formalism We compare these results with those, distinctly different, obtained by the classical molecular dynamics.PACS: 61.80.Az, 61.48.Gh, 61.80.Jh, 34.50.Dy.

No MeSH data available.


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SCC-DFTB and LDA-DFT [25]potential energies of the hydrogen-coronene interaction.
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Figure 1: SCC-DFTB and LDA-DFT [25]potential energies of the hydrogen-coronene interaction.

Mentions: To safely allow for high-energy bombardment simulations (in our case 200 eV), we use a refitted version of the original DFTB PBC-0-3 [13] parameters obtained by fitting to the ZBL [14] repulsive interactions at short distances (< 0.2 Å). The PBC-0-3 parameters used here have already shown good results for the hydrogenation of periodic graphene [23] at thermal energies. We show in Figure 1 the potential energy curves of a hydrogen atom interacting with a coronene molecule obtained by the SCC-DFTB using PBC-0-3/ZBL parameters and by DFT using a local density approximation functional [24]. At distances closer than 1.5 Å, agreement between DFT [25] and DFTB potentials is quite good. Between 1.5 and 4 Å, DFTB potentials overestimate bond strength, and wells are about 0.5 Å closer to the surface than their DFTB counterparts. Also notable is the lack of convergence of the three potentials until they approach 0 eV. Although SCC-DFTB underestimates bonding at the bond center and lattice point positions, these are qualitatively similar to DFT potentials [25]. The problem of thermal atom adsorption gave rise to many experimental and theoretical papers [7,15-19] and references therein. The previously reported SCC-DFTB studies [26] of collision-induced reactions in carbon materials within the same energy range considered here were in excellent agreement with experimental findings. Additional comparisons between DFT and SCC-DFTB are contained in the studies of Zheng et al. and Elstner [27-29].


Detection of hydrogen using graphene.

Ehemann RC, Krstić PS, Dadras J, Kent PR, Jakowski J - Nanoscale Res Lett (2012)

SCC-DFTB and LDA-DFT [25]potential energies of the hydrogen-coronene interaction.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3369821&req=5

Figure 1: SCC-DFTB and LDA-DFT [25]potential energies of the hydrogen-coronene interaction.
Mentions: To safely allow for high-energy bombardment simulations (in our case 200 eV), we use a refitted version of the original DFTB PBC-0-3 [13] parameters obtained by fitting to the ZBL [14] repulsive interactions at short distances (< 0.2 Å). The PBC-0-3 parameters used here have already shown good results for the hydrogenation of periodic graphene [23] at thermal energies. We show in Figure 1 the potential energy curves of a hydrogen atom interacting with a coronene molecule obtained by the SCC-DFTB using PBC-0-3/ZBL parameters and by DFT using a local density approximation functional [24]. At distances closer than 1.5 Å, agreement between DFT [25] and DFTB potentials is quite good. Between 1.5 and 4 Å, DFTB potentials overestimate bond strength, and wells are about 0.5 Å closer to the surface than their DFTB counterparts. Also notable is the lack of convergence of the three potentials until they approach 0 eV. Although SCC-DFTB underestimates bonding at the bond center and lattice point positions, these are qualitatively similar to DFT potentials [25]. The problem of thermal atom adsorption gave rise to many experimental and theoretical papers [7,15-19] and references therein. The previously reported SCC-DFTB studies [26] of collision-induced reactions in carbon materials within the same energy range considered here were in excellent agreement with experimental findings. Additional comparisons between DFT and SCC-DFTB are contained in the studies of Zheng et al. and Elstner [27-29].

Bottom Line: Irradiation dynamics of a single graphene sheet bombarded by hydrogen atoms is studied in the incident energy range of 0.1 to 200 eV.Results for reflection, transmission, and adsorption probabilities, as well as effects of a single adsorbed atom to the electronic properties of graphene, are obtained by the quantum-classical Monte Carlo molecular dynamics within a self-consistent-charge-density functional tight binding formalism We compare these results with those, distinctly different, obtained by the classical molecular dynamics.PACS: 61.80.Az, 61.48.Gh, 61.80.Jh, 34.50.Dy.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Physics and Astronomy, Middle Tennessee State University, Murfreesboro, TN, 37130, USA. rce2g@mtmail.mtsu.edu.

ABSTRACT
Irradiation dynamics of a single graphene sheet bombarded by hydrogen atoms is studied in the incident energy range of 0.1 to 200 eV. Results for reflection, transmission, and adsorption probabilities, as well as effects of a single adsorbed atom to the electronic properties of graphene, are obtained by the quantum-classical Monte Carlo molecular dynamics within a self-consistent-charge-density functional tight binding formalism We compare these results with those, distinctly different, obtained by the classical molecular dynamics.PACS: 61.80.Az, 61.48.Gh, 61.80.Jh, 34.50.Dy.

No MeSH data available.


Related in: MedlinePlus