Titania-coated platinum thin films by MOCVD: electrochemical and photoelectrochemical properties

Pt films are deposited on glass rods from Pt(acac)(2) and H2O in the thickness range 10-200 nm. Voltammetric measurements show that a 100 nm Pt film behaves like a bulk Pt electrode. A series of 100 nm Pt films are then coated with anatase TiO2 films 15-100 nm thick using Ti((OPr)-Pr-i)(4) as the precursor. The electrochemical properties of the Pt-TiO2 electrodes, investigated by cyclic voltammetry in aqueous solutions, indicate that the passivating TiO2 layer induces some kinetic inhibitions into the heterogeneous electron transfer process of Ru(NH3)(6)(3+), which is utilized as a probe molecule. The photoelectrochemical performance of the Pt-TiO2 films demonstrates an optimum behavior for 100 nm TiO2 coatings. The photocatalytic properties of the Pt-TiO2 films can be exploited for electrocatalytic applications in sensor technology.