REACTION OF OXYGEN REDUCTION ON THE SURFACE OF AU ON TI WITH OXIDEFORMED POTENTIODYNAMICALLY BEFORE AND AFTER THE DEPOSITION OF AU

Abstract

One of the most important reactions for electrochemical science and technology is the electrocatalytic reduction ofoxygen. It is particularly relevant in fuel cells because it is slow to react and requires high overpotentials. This workaims to study electrodes with deposits of Au on Ti obtained by electrodeposition. The substrates have undergone po-tentiodynamic growths of oxides before deposition for some electrodes and after deposition for other electrodes understudy, at different final potentials. Both procedures resulted in the formation of a composite Au layer on the Ti surface.The electrochemical behavior of these composite layers was examined in a 0.01 M HClO4solution, both oxygen-freeand oxygen-saturated, and compared with the behavior of Ti as a target, using the cyclic voltammetry technique. In thepotential region of the oxygen reduction reaction (RRO), the Au layer on the Ti obtained by first performing the Audeposition and then the growth of the anode oxide showed a better response, not only in the onset potential of the RRO,but also in the current densities. In all cases the voltammetry curves of the Au and TiO2 composite layers were similarto those shown by the Au polycrystalline.