Facile Fabrication of Photoelectrochemical Assemblies Consisting of Gold Nanoparticles and a Tris(2,2‘-bipyridine)ruthenium(II)−Viologen Linked Thiol

Abstract

Facile fabrication of a modified electrode with gold nanoparticles and a tris(2,2'-bipyridine)ruthenium(II)−viologen linked thiol (RuVS) is described. First, the gold nanoparticles (14 ± 1 nm) were precipitated onto the gold electrode in an aqueous solution. Then, this electrode was immersed into a acetonitrile solution containing RuVS, to immobilize it via Au−S bonding. Scanning electron micrographs show agglomeration and island formation of the gold particles on the electrode and 1−3 μm thickness of the deposition. In cyclic voltammetry, a redox couple due to one-electron reduction of the viologen moiety was clearly observed and its intensity increased with increasing the extent of deposition. The anodic photocurrent from the modified electrode ascribed to ruthenium-complex-sensitized redox cycles was clearly observed and was more than 15-fold larger as compared with that of the flat electrode (without gold particles).