Oxide electrodes. A new technique to bind oxide powders onto Au substrates

A technique is described to obtain supported oxide powder electrodes. Preformed powders are first embedded into a gold substrate, as reported by Totir et al. [D.A. Totir, B.D. Cahan, D.A. Scherson, Electrochim. Acta 45 (1999) 161], and then made to adhere in place by heating at T∼260–300 °C in flowing oxygen. This latter step is of the greatest importance to obtain reliable electrodes for use in aqueous electrolytes. Electrode stability and reproducibility are examined on voltammetric and O2 evolution results using Co3O4 as a sensitive test oxide material. Many independent Au–Co3O4 electrodes compare favourably with one another and with graphite-supported electrodes from an unrelated, room temperature binding technique. Substrate and oxide-substrate junction effects are minimised.