Surface morphology and electrochemical characterization of electrodeposited Ni-Mo nanocomposites as cathodes for hydrogen evolution

Ni-Mo nanocomposite coatings (18-32 nm) were prepared by electrodeposition of nickel from a nickel salt bath containing suspended Mo nanoparticles. All the coatings have been deposited under galvanostatic conditions using current densities in the range 5-80 mA/cm(2). According to structural investigation carried out by X-ray diffraction, the obtained coatings consisted of crystalline Mo phase incorporated into Ni matrix. The molybdenum content diminished with increasing the deposition current density and ranged between similar to 6 and similar to 17% Mo. The crystallite size and the surface roughness increased by raising the current density. A remarkable deterioration in the corrosion resistance of Ni-Mo composites was observed with the increase of Mo content due to crystallite size-refining and surface roughness effect. Electrocatalytic effect for hydrogen production was improved mainly as a result of increasing the surface roughness and thus providing more accessible surface area. (C) 2012 Elsevier B.V. All rights reserved.