Biomedical Engineering Reference
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Figure 5.2
Visual guides describing adsorbed H-induced reconstruction
of graphene: (a) displacement of C atoms from the original
graphene plane, and (b) local planar distortion. For the
latter, dashed (solid) contours indicate downward (upward)
distortion, as illustrated in c (b). Contours are separated by
0.02 Å. The position of the H atom is marked by triangles.
The darker is the contour shading, the greater is the extent of
C atom tetrahedrization, as illustrated in Fig. 5.2c and d. It becomes
apparent that C-C bonds, within a certain range of the adsite, move
out of their initial planar geometries in order to minimize the energy
of the system. The results also show that a bridge site adsorption of
H atom is endothermic (~0.1 eV), while the hollow site is not a local
energy minimum for the H atom on graphene. Despite the small size
of the hydrogen atom, there is an activation barrier of 4.0 eV when H
penetrates the graphene sheet through the hollow site.
Figure 5.3
Potential energy surface and effective adsorption reaction
pathway of H on graphene. Contour spacing is 0.1 eV.
(Reproduced from Ref. [5].)
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