Improved stability of PtOx Sol-gel-modified diamond electrodes covered with a Nafion® film

Abstract

The modification of boron-doped diamond (BDD) electrodes with platinum oxide particles deposited by the Sol-gel method and using several pre- and post-treatments of the surface is described. The electrochemical stability of the resulting catalytic coatings was evaluated by cyclic voltammetry in acid medium and was much greater than those previously reported in the literature for others deposition methods. A thermal pre-treatment of the BDD surface yielded electrodes that retained 91.6% of the coated material after 1000 voltammetric cycles carried out between the water decomposition reactions. The application of a Nafion® film on top of the coating preserved integrally the deposited platinum oxide. The use of such modified electrodes for practical applications is now feasible under the present experimental conditions. ©2005 Sociedade Brasileira de Química.