Electrochemical nanoscale templating: laterally self-aligned growth of organic-metal nanostructures

The electrodeposition of Ag into organized surfactant templates adsorbed onto (22 × √3) reconstructed Au(111) is investigated by in situ electrochemical scanning tunneling microscopy. Ag(+) concentrations of as low as 2.5 × 10(-6) M allow the visualization of the electrochemical molecular templating effect of a sodium dodecyl sulfate (SDS) adlayer. The SDS hemicylindrical stripes determine the adsorption sites of the Ag(+) ions and the directionality of Ag nanodeposition. The SDS-Ag nanostructures grow along the long axis of SDS hemicylindrical stripes, and an interaction of Ag with the Au(111) substrate leads to a structural change in the SDS stripe pattern. The SDS-Ag nanostructures undergo dynamic rearrangement in response to changes in the applied electrode potential. At negative potentials, the orientations of SDS-Ag nanostructures are pinned by the (22 × √3) reconstructed pattern. Furthermore, observed differences in Ag nanostructuring on Au(111) without molecular templates (i.e., on a bare Au(111) surface) confirm the role of self-assembled organic templates in producing metal-organic nanostructures under control of the surface potential, which can determine the feature size, shape, and period of the metal nanostructure arrays.