Hydrogen molecule capacity physisorption on BC3 monolayer: First-principles calculations

Abstract

In this investigation, we studied the hydrogen molecule adsorption on the BC3 sheet via first-principles calculations. First, we have identified the most stable sites of hydrogen molecule adsorption on the BC3 surface. It is estimated from the calculations that the most stable site is located in the center of the hexagon of carbon atoms where the hydrogen molecule is positioned vertically above BC3 sheet, as well as the adsorption energy Eads is about −7.2642 kcal mol−1, whereas the 3.10 Å is the closest stable distance. The density of state calculation shows that upon adsorption of H2 molecules onto the BC3 surface, it keeps its semiconducting behavior with both methods the Marzarie Vanderbilt and the Tetrahedron method. An investigation of the migration paths between the different positions shows a capability of hydrogen molecule to diffuse between the positions, separated by a small barrier of energy amounting to 2.25 meV. The BC3 sheet is demonstrated to possess the capability of adsorbing 11 hydrogen molecules, with a gravimetric capacity of 10.51 wt%, with a desorption temperature of 205.33 K. According to the above results, the BC3 sheet can be a very interesting prospect for hydrogen storage.