Electric field-induced charge transfer of (Bu4N)(2)[Ru(dcbpyH)(2)-(NCS)(2)] on gold, silver, and copper electrode surfaces investigated by means of surface-enhanced Raman scattering

Abstract

The potential-induced charge transfer of the dye (Bu4N)(2)[Ru(dcbpyH)(2)-(NCS)(2)] (N719) on Au, Ag, and Cu electrode surfaces has been examined by surface-enhanced Raman scattering (SERS) in the applied voltage range between 0.0 and -0.8 V. N719 is assumed to have a relatively perpendicular geometry with its bipyridine ring on the metal surfaces. A strong appearance of the carboxylate band at similar to 1370 cm(-1) indicates that the carboxyl group will likely be deprotonated on the metal surfaces. As the electric potential is shifted from -0.8 to 0.0 V, the v(NCS) band at similar to 2100 cm(-1) on the electrode surfaces appears to undergo a shift in frequency and intensity change. This indicated that the charge transfer between the dye and metal electrode surface's had occurred. Electric-field-dependent charge transfer differs somewhat depending on the type of metal surfaces as suggested from the dissimilar frequency positions of the v(NCS) band.