Evolution of hydrogen and its sorption on remarkable active amorphous smooth NiP(x) electrodes

Abstract

Hydrogen evolution reaction was studied on electrolytically prepared amorphous smooth NiP(x) layers with a phosphorus content of 3 to 14 wt%. NiP(x) electrodes with a low P content about 3 wt% are very active. At the potential E = - 0.2 V [rhe] in 1 N KOH at 23 °C the current density of the hydrogen evolution is ≈0.2 A cm-2, which is approximately 10 times higher than on platinum and 300 times higher than on nickel. The polarization curve NiP(3%) has a low slope b ≈ 0.058 V dec-1 in the range of current densities 0.001-1 A cm-2. This low slope is caused probably by a barrierless electron transfer reaction mechanism. High activity of amorphous NiP(3) electrodes is caused by the ability of these electrodes to adsorb and absorb great amounts of hydrogen, which changes the electron structure of the basic metal. The thermal treatment of layers at approximately 150 °C causes the crystallisation of layers and the loss both of the activity and the ability to sorb hydrogen. © 1995.