Hydrogen transport on graphene: Competition of mobility and desorption

Abstract

The results of molecular dynamics (MD) simulations of atomic hydrogen kinetics on graphene are presented. The simulations involve a combination of approaches based on Brenner carbon-hydrogen potential and firstprinciples force calculations. Both kinds of MD calculations predict very similar qualitative trends and reproduce equally well the features of hydrogen behavior, even such sophisticated modes as long correlated jump chains. Both approaches agree that chemisorbed hydrogen diffusion on graphene is strongly limited by thermal desorption. This limitation rules out long-range diffusion of hydrogen on graphene but does not exclude the short-range hydrogen diffusion contribution to hydrogen cluster nucleation and growth.

Theoretical study of the dynamics of atomic hydrogen adsorbed on graphene multilayers

“…The electronic state thus induced will correspond to that of a nonmagnetic insulator for large concentrations [1][2][3][4][5], an antiferromagnet for intermediate concentrations [19], or a paramagnet for low concentrations [12]. At room temperature, which for practical applications is the most interesting case, both desorption and diffusion processes are, in principle, active [20][21][22][23][24][25][26][27][28][29][30]. If desorption rates are larger than diffusion ones, the sample will loose H from both sublattices, but at different rates.…”

Total Ionizing Dose Effects on hBN Encapsulated Graphene Devices

“…7. The migration barrier of H on graphene is eV [43], [44]. Hydrogen atoms adsorbed on graphene may cause an increase in electron concentration in the graphene layer.…”

Calculations of adsorption energies, coadsorptions, and diffusion barriers of H atoms, and the H2 formation on a nanographene surface (coronene)

“…Polycyclic aromatic hydrocarbons (PAHs) play an important role in mesoporous activated carbons because they provide adsorption sites for radicals generated during thermal processes . There exist also the possibility of using carbon nanostructures (nanographenes, e.g., coronene) formed of PAHs and graphenes as storage materials of atomic hydrogen . In addition, PAHs are very relevant components of petroleum and may act as a trap for radicals produced in the cracking of hydrocarbons .…”