Improving Electrocatalytic Activity of LaNiO3 Films by Deposition on Foam Nickel Substrates

• Autor(a) principal: Soares,C.O.
• Data de Publicação: 2011
• Outros Autores: Carvalho,M.D., Jorge,M.E. Melo, Gomes,A., Silva,R.A., Rangel,C.M., Pereira,M.I. da Silva
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://scielo.pt/scielo.php?script=sci_arttext&pid=S0872-19042011000500004
• topic: LaNiO3 electrode; nickel foam; oxygen evolution; electrocatalysis

In this work LaNiO3 oxide was prepared by a self-combustion method using citric acid. The electrodes were obtained by coating a nickel foam support with the oxide suspension. Optical microscopy and cyclic voltammetry were used on the electrodes characterization. The evaluation of the electrodes electrocatalytic activity, towards the oxygen evolution reaction in alkaline medium, was performed by means of steady state measurements. The reaction follows a first order kinetics, with respect to OH- concentration, with Tafel slopes close to 40 mV, for low overpotentials. Based on the apparent and real current densities it was possible to conclude that the increase on the electrode activity, when compared with the published data, is mostly related to geometric factors. This fact has been associated with the high electrode/electrolyte contact area provided by the foam nickel substrate. Synergetic effects between the Ni foam and the perovskite oxide cannot be discarded.