Molecular Dynamics Simulation of Collisions between Hydrogen and Graphite

TL;DR

This study uses molecular dynamics simulations to explore how hydrogen interacts with graphite, revealing energy-dependent adsorption, reflection, and penetration behaviors relevant for understanding sputtering mechanisms.

Contribution

It introduces a modified Brenner REBO potential to simulate hydrogen-graphite collisions, identifying energy regimes that determine adsorption, reflection, or penetration.

Findings

Hydrogen adsorption rate depends on incident energy, not temperature.

At energies below 100 eV, hydrogen either adsorbs, reflects, or penetrates graphite.

Low-energy hydrogen impacts distort graphene structure.

Abstract

Hydrogen adsorption by graphite is examined by classical molecular dynamics simulation using a modified Brenner REBO potential. Such interactions are typical in chemical sputtering experiments, and knowledge of the fundamental behavior of hydrogen and graphene in collisional conditions is essential for modeling the sputtering mechanism. The hydrogen adsorption rate is found to be dependent on the incident hydrogen energy and not on graphene temperature. Rather than destroying the graphene, hydrogen incidence at energies of less than 100 eV can be classified into three regimes of adsorption, reflection and penetration through one or more graphene layers. Incidence at the lowest energies is shown to distort the graphene structure.