Relationship between Surface Heterogeneity and Electrochemical Interface Behavior of the TiAl Alloy Electrode

A quantitative description of surface micro-morphology is a topic worthy of attention to establish the relationship between the surface texture and electrochemical behavior of the electrode interface. In this paper, box-counting dimension, multifractal spectrum, and lacunarity were applied to characterize quantitatively the surface heterogeneity of the TiAl alloy electrode, and electrochemical impedance spectroscopy was used to study the electrochemical behavior of the TiAl alloy electrode interface. The characteristic parameters of fractal structures and electrochemical interfaces were extracted, and the relationships between them were built. The results prove that box-counting dimension has no specific relations with the electrochemical property of the TiAl alloy electrode interface, and the main reason is that it has incomplete information on spatial distribution of the surface texture. The characteristic parameter B of multifractal spectrum at high magnification (2100X) maintains a close relation with the electrochemical parameter of the TiAl alloy electrode interface. Besides, there is a tight connection between the integral lacunarity at the magnification factor of 2100x and the interfacial parameters R-ct,Q(dl), and n of the TiAl alloy electrode, respectively. The results also prove that multifractal spectrum and lacunarity are suitable for describing the interface topography of the TiAl alloy electrode and are beneficial to explain the electrochemical behavior of the TiAl alloy electrode interface.