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

In the last years many attention has been dedicated to the increase of performance of Nichel based electrodes to use in water-alkaline electrolyzes. In our preliminary work we have shown that alkaline electrolyzer made with Ni nanowires covered with IrO2 (side oxygen evolution) nanoparticles and a Ni sheet (side hydrogen evolution) have very good and stable performance also at room temperature [1]. In this work, to obtain a complete nanostructured electrolyzer, the attention was focused on the fabrication of electrodes for hydrogen evolution. In particular, by metal displacement deposition we have grown on Ni nanowires electrodes, nanoparticles of Pd with the aim to enhance the electrocatalytic efficiency of Ni nanowires. Several parameter of galvanic process of Pd deposition were studied, such as deposition time, concentration of palladium precursor in solution and so on. The results on the growth and characterization of these nanostructured composite electrodes will be presented and discussed. Besides, the preliminary test on the electrochemical performance of nanostructured electrolyzer, carried out at constant current in 1M aqueous solution of potassium hydroxide, will be also reported. [1] M. Battaglia, R. Inguanta, S. Piazza, C. Sunseri. International Journal of Hydrogen Energy 39, 16797-16805.