Influence of substrate on the electrodeposition of nickel-molybdenum alloys

The electrodeposition of nickel-molybdenum alloy has been studied on various substrates, with the aim of determining the influence of hydrogen evolution on the formation of the deposit. Transient electrochemical methods were used. Three types of substrates were used. Glassy carbon in which hydrogen absorption cannot occur, palladium in which hydrogen diffusion is rapid, and nickel. Good and thick deposits were obtained on glassy carbon and annealed ultra pure nickel. On palladium no deposit was formed. The importance of hydrogen in the formation of the deposit was confirmed. Codeposition occurs in the same potential range as hydrogen evolution, and therefore hydrogen is trapped in the expanding lattice as seen by its oxidation during anodic polarization.