Electrochemical and Photoelectrochemical Investigation of New Electrostatic Self-Assembled Films Based on Prussian Blue and a Binuclear Ru(II) Complex

Abstract

New hybrid multilayer films containing Prussian blue (PB) and a binuclear Ru(II) complex were successfully fabricated using the electrostatic layer-by-layer self-assembly technique. The process was carefully monitored by ultraviolet-visible (UV-vis) spectroscopy. A linear increase in the UV-vis absorbance with the number of deposited layers indicated that the film deposition was uniform and reproducible. The electrochemical and photoelectrochemical properties of these hybrid multilayer films were investigated in an aqueous Na2SO4 solution. PB and the binuclear Ru(II) complex assembled in the film were redox active with surface confined characteristics. The surface concentration and molecular area of RuL in the film were calculated according to a UV-vis absorption spectrum and cyclic voltammetry, respectively. The photocurrent generated by switching on the light irradiation of the film increased linearly as the deposited bilayers increased. The photocurrent action spectrum was in agreement with metal-to-ligand charge-transfer (MLCT) band of RuL in the absorption spectrum, which indicated that the photocurrent was generated based on MLCT excitation of the RuL in the (PB/RuL) film.