Determinación del área de superficie real de electrodos de titanio modificado con platino por voltamperometría cíclica

Abstract

The surface area of Ti/TiO2-Pt electrodes (ASr) in contact with 0.010 M HClO4 solutions was determined by Cyclic Voltammetry (CV) and Atomic Force Microscopy (AFM) techniques. The Ti/Pt/TiO2 electrodes with different amounts of electrodeposited Pt (1, 5 and 10 seconds) were polarized up to 1.5 V vs. Ag/AgCl (sat. KCl) and stabilized at the final potential during 15 minutes. The highest limit of oxygen adsorption and/or oxide formation was choosen for potentials before the oxygen evolution, and the current corresponding to the region were the oxygen desorption takes place was integrated. These values were used as a parameter to determine the ASr for the different electrodes. The results demonstrate that the Ti/Pt/TiO2 (10 seconds) electrodes have the largest area in contact with the electrolyte. A second method used to determine the ASr was AFM. The results obtained by the two methods were in good correlation.