Fabrication of Nanostructured Ni and Ni-IrO2 electrodes for wateralkaline electrolyzer

In the field of water-alkaline electrolyzer, the develop of nanoporous nickel electrodes with low cost and high electrocatalysis efficiency is one of the potential approaches to increase their performance [1]. To obtain nanostructured electrodes, a facile approach is that of template electrosynthesis. With this method we have obtained electrodes made of nanowires of Ni that have a very high surface area. These electrode were obtained by a two-step procedure allowing to obtain an ordered array of Ni nanowires that completely covering the surface of current collector made of the same material. Besides, by amperostatic deposition we have covered these electrode with nanoparticles of IrO2 electrocatalyst. In this work, the results on the growth and characterization of these nanostructured electrode will be presented and discussed. Ni NWs were obtained by pulsed potential deposition into polycarbonate membranes [2]. IrO2 electrocatalyst was deposited on Ni NWs by different electrochemical techniques, like cyclic voltammetry and potentiostatic deposition [3]. For comparison, IrO2 electrocatalyst was also deposited on a Ni flat substrate. All electrodes were characterized by SEM, EDS, and XRD analyses. Moreover, the preliminary test on the electrochemical performances, carried out at constant current in 1M aqueous solution of potassium hydroxide, will be also reported. [1] D. Pletcher, X. Li Intern. J. Hydrogen energy 36 (2011) 15089. [2] R. Inguanta, S. Piazza, C. Sunseri Electrochem. Acta 53 (2008) 5766. [3] E. Ahlberg, P. Steegstra Electrochem. Acta 68 (2012) 206.