Absorption of atomic hydrogen into graphite via the armchair edge: A first principles study

• Main Authors: Arboleda, Nelson B., Jr., Kasai, Hideaki
• Format: text
• Published: Animo Repository 2011
• Subjects: Hydrogen—Absorption and adsorption; Nanostructured materials; Graphite; Physics
• Online Access: https://animorepository.dlsu.edu.ph/faculty_research/11934
• Institution: De La Salle University

We investigate the absorption behaviors of atomic hydrogen (H) incident on graphite via the armchair edge. DFT-based total-energy calculations performed show the existence of a reaction path where H can enter the region between graphite sheets. A strong trap for H atom exists just above the surface of C atoms, which strongly suggests that H termination of the edge C atoms' dangling bonds most likely will occur during absorption. Beyond the surface, the negative potential energy along the reaction path fluctuates and seems to approach zero, which indicates that H absorption deeper into the subsurface becomes more difficult without reconstruction. During absorption, H stays near one of the graphite sheets. H motion parallel to a C row is also observed, while interlayer hopping is most unlikely to occur, Also, the barrier to H desorption between rows is always less than that to absorption.