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Journal of Physical Chemistry A 121, 5520 (2017)

ISSN: 1089-5639, SCI

Accelerating Dynamics of H on Graphene by Coadsorbates

Manh-Thuong Nguyen and Pham Nam Phong

There are several factors that affect the dynamics of adsorbed hydrogen atoms on a carbon surface. Using density functional calculations we show that coadsorption can be a highly influential factor. The diffusion of hydrogen adsorbed on graphene is explored in the presence of H-containing molecules. Without coadsorbates the diffusion barrier of H on graphene is 0.94 eV, while with water/ammonia it is 0.85/0.12 eV. The low barrier in the case of ammonia is attributed to the formation of a stable intermediate state NH4, while such a stable state is not found in the case of water. In addition, hydrogen fluoride, hydrogen sulfide, arsine, and phosphine were also considered. We found that stronger hydrogen−hydride bonds lead to lower diffusion barriers of H on graphene.

DOI: 10.1021/acs.jpca.7b02577