Photoelectrochemical behaviour of ruthenium(II) complex layers at a platinum electrode immobilized by the common-ion effect in aqueous electrolyte solution

Abstract

The photoelectrochemical behaviour of multi-molecular layers of Ru(bipy)₃(BPh₄)₂, where bipy = 2,2′-bipyridine, immobilized on a platinum electrode by the common-ion effect was studied under potentiostatic conditions in an aqueous electrolyte solution with no added redox agents. Upon illumination, anodic photocurrents were generally observed, the quantum efficiency being 3.5 × 10^–4 at 480 nm with an applied potential of +150 mV (saturated calomel electrode). The effects of applied potential, light intensity, and pH were also examined. During each experiment, the surface layer stabilized by the common-ion effect was sufficiently stable to obtain reproducible data. The results are interpreted in terms of the reaction of a photo-generated ruthenium(III) complex with OH^– ions.