The influence of surface roughness on the electrochemical activity of nickel electrodes

Nickel micro- and nanostructures have unique magnetic and electrochemical properties and are widely applied in chemical current sources. The goal of this work was to develop the methods of preparation of nickel electrodes and to study an electrochemically active surface with given properties. A standard electrode (spongy nickel), and an electrode with a roughened surface, chemically modified by nickel fibers, were taken as objects of analysis. Surface roughness was found to be an important parameter influencing the electrode electrochemical activity. For quantitative estimation of roughness, the fractal dimension of the surface of the electrodes was calculated. It was revealed that, with the growth of the fractal dimension, the surface area and the electrochemical activity of the electrodes increase. An electrode with a roughened surface for electrochemical sensors was proposed, which can also find application in optical gas sensors, chemical current sources, catalysis, and electrochromic devices.