Density Functional Theory Study of the Adsorption of Alkanethiols on Cu(111), Ag(111),

F. P. COMETTO; P. PAREDES OLIVERA; V. A. MACAGNO; E. M. PATRITO

JOURNAL OF PHYSICAL CHEMISTRY B

American Chemical Society

Año: 2005 vol. 109 p. 21737 - 21737

1089-5647

p>The structure, the surface bonding, and the energetics of alkanethiols adsorbed on Cu(111), Ag(111), and Au(111) surfaces were studied under low and high coverages. The potential energy surfaces (PES) for the thiol/metal interaction were investigated in the absence and presence of externally applied electric fields in order to simulate the effect of the electrode potential on the surface bonding. The electric field affects the corrugation of the PES which decreases for negative fields and increases for positive fields. In the structural investigation, we considered the relaxation of the adsorbate and the surface. The highest relaxation in a direction perpendicular to the surface was observed for gold atoms, whereas silver atoms presented the highest relaxation in a plane parallel to the surface. The surface relaxation is more important in the low coverage limit. The surface bonding was investigated by means of the total and projected density of states analysis. The highest ionic cha