Production and properties of electrolytic Ni-P-TiO2 composite layers

Ni-P-TiO2 active cathodes were prepared by simultaneous electrodeposition of Ni and TiO2 on a Cu substrate from a solution in which TiO2 particles were suspended by stirring. Electrodeposition was carried out under galvanostatic conditions at a current density of 240 mA cm(-2) for 0.5 h. For comparison, Ni-P layers were also obtained under the same conditions. Following heat treatment in air two further types of electrode material were obtained. X-ray diffractometer, scanning electron microscope, X-ray probe microanalyser, Auger spectroscope and atomic absorption spectroscope were used for physical and chemical characterization of the layers. It was ascertained that the introduction of TiO2 to the amorphous Ni-P layers leads to an increase in the rate of hydrogen evolution in comparison with conventional Ni-P layers irrespective of environment. Heat treatment does not exert an appreciable influence on the rate of hydrogen evolution on a Ni-P electrode and induces a slight inhibition of hydrogen evolution on a Ni-P-TiO2 electrode in acid environment.