Characterisation of titanium oxide films by potentiodynamic polarisation and electrochemical impedance spectroscopy

Titanium is used for many applications, ranging from chemical, biomedical, and decorative. Its versatility is due to its excellent mechanical properties, high corrosion resistance and biocompatibility. Moreover, its oxides, grown by anodising techniques, can have different colourations, which make them useful for applications related to art and architecture; in their crystalline form, they show excellent photochemical properties, which are widely used in chemical synthesis and in the cleansing of pollutants. The aim of this work is to characterise the titanium dioxide films, grown anodically in sulphuric acid 0.5 M at three different anodising potentials, by potentiodynamic polarisation and electrochemical impedance spectroscopy (EIS). When comparing the obtained oxide films, a progressive increment in their crystallinity and electrical resistance was observed with the increase of the anodising potential.