Nanoscale structural characteristics of photodissolved gold (111) single crystalline surface

The effect of photoillumination on electrochemical reactions of a gold electrode in KCI electrolyte solution was investigated. The electrode was dissolved by positive polarization in the electrolyte Solution. Anodic current increased when the electrode was illuminated by 830-nm light. Scanning tunneling microscope images proved that dissolution of the gold electrode was accelerated by the photoillumination. The surface of the photodissolved electrode consisted of islands with a flat top and relatively narrow size distribution. In some cases, uniform structure consisted of small islands was formed by the illumination. The contribution of a highly localized photoexcitation mode at the surface was discussed to explain the characteristics of the photoformed surface nanostructure.