Sputtered nickel and nickel-molybdenum films as electrocatalysts for the Hydrogen Evolution Reaction

Nanocrystalline thin Ni, Ni;The activity and the rate determining reaction step for these electrodes in the HER was determined through 'steady state' (Tafel) polarization tests. The changes in electrode activity for the HER, after being exposed to the potential regime of the Oxygen Evolution Reaction (OER), was determine through cyclic voltammetry (CV) experiments. Optical and electron (SEM and TEM) microscopy were utilized to study the changes in the surface morphologies of the crystalline and sputtered film materials before, during and after performing these polarization experiments.;The experimental results indicated better activity in the HER could be achieved after 200 continuous potential cycles into the OER, for both groups of materials. The sputtered films showed much better activity for the HER than their crystalline counter parts, in the cases of before and after potential cycling. The addition of Mo to Ni was determined to have increased the activity towards the HER for the sputtered film materials, whereas a decrease in the HER activity was detected for the crystalline materials. Molybdenum was not detected to have dissolved out of the alloy during the course of the tests. (Abstract shortened by UMI.).