Full text loading...
H (red) adsorbed on a cluster of atoms forming a honeycomb lattice (carbon dangling bonds on the border have been saturated with hydrogen atoms). The adsorption of H disturbs the planarity of the cluster and changes the C–C distances around the adsorption site over a large distance.
Two H atoms (red) adsorbed on both sides of a cell representing a two-dimensional infinite system where the chemisorption problem is solved using a plane-wave extended basis set. Notice the buckling induced by the adsorption of H affecting C–C bond lengths located at distances comparable to the size of the cell.
Binding energy (eV) of H on graphene vs C–C stretch (%) calculated for (a) cluster in Fig. 1, and MIDI/B3LYP chemistry (circles and solid line), and (b) a periodic unit cell using plane waves and LDA (triangles and dashed line). Lines are least-squares fits to guide the eyes. The LDA result has been corrected by an offset, 0.866 eV, to allow the comparison of slopes.
Comparison of geometrical parameters for the three models considered for H adsorbed on graphene. In the two H have been adsorbed on both sides of the layer separated by . The following parameters are listed: buckling of the C atom binding directly to the adsorbed H ( in angstroms), the length of this bond ( in angstroms), the angle defined by H, , and ( in degrees), and the distance from to its nearest neighbors ( in angstroms).
Article metrics loading...