Photo-induced metal deposition onto a Au electrode in solution

The effect of photo-irradiation on metal deposition onto several Au electrodes was investigated. The metal deposition can be controlled by photo-irradiation at the metal/solution interface. Although the deposition proceeds when the ions are excited by the photo-irradiation at the electrode whose potential is maintained at an appropriate potential, the process can be accelerated by the photo-excitation of electrons in the metal electrode. The introduction of surface roughness for the excitation of surface plasmon was useful in improving the reaction efficiency. The contribution of the plasmon mode was successfully applied to construct a single metal-dot structure on the smooth Au(1 1 1) surface in the vicinity of the thin metal tip. Cu metal nano-dot 15 nm in size and 1 nm in height can be prepared by the photo-irradiation of an atomically smooth surface of the metal electrode only at a point in the vicinity of the metal tip.