Influence of the stereometric and morphometric structure of composite coatings on the hydrogen evolution process

Nickel-based composite coatings, in the matrix of which there is an electrodeposited powder of metals (W, Ti, Mo, Al, etc.) that cannot be easily deposited from aqueous solutions, are of great significance in practical applications. The effectiveness of, e.g., the hydrogen evolution reaction on such coatings is a function of the parameters of their electrolytic production and thermal treatment. Both processes determine the phase composition and structure of the coatings as well as their surface morphology. The surface stereometric structure (SSS) is vital, inter alia, for the effectiveness of hydrogen electroevolution. In this paper, the possibility is shown of characterizing SSS by means of parameters and a functional 3D description of such properties of the coatings as: the distribution of the cross-sectional area of the pores, the area of their development and volume, and their number as a function of depth. Synergism of the stereometric structural parameters' and intermetallic phases' effects on modeling the electrochemical activity of the coatings is shown. (c) 2005 Elsevier Inc. All rights reserved.