Application-wise nanostructuring of anodic films on titanium: a review

The interest in titanium and its oxides keeps growing on account of their peculiar engineered properties, which find applications in several fields, from architecture to bioengineering, from automotive to photovoltaic cells and photocatalytic devices, as well as to produce self-cleaning surfaces. This review intends to provide an overview of anodic oxidation treatments currently applied to form nanostructured oxide layers on titanium, with special reference to their whole range of applications. The different procedures and parameters of anodic oxidation will be described, giving information on the main oxide characteristics achievable: thickness, morphology, structure and composition. An analysis of the fields of application associated with specific oxide characteristics will be provided, in order to highlight the variety of properties that can be obtained, and the importance of tuning such properties as a function of the specific application.