Unveiling the Power of Titanium Dioxide for Energy Storage and Electrochemical Technologies

Abstract Titanium dioxide nanotubes (TiO 2 NTs) have been widely investigated in the past 20 years due to a variety of possible applications of this material. Indeed, their high surface area and tunable morphology can easily implement key features of TiO 2 , such as its biocompatibility and photo‐ and electrocatalytic properties. This combination makes TiO 2 NTs perfect candidates for multifunctional applications ranging from biomedical application to sensing and energy devices. Herein, we present TiO 2 NTs grown by anodic oxidation on top of a titanium foil in an ethylene glycol‐based electrolyte with NH 4 F. The as‐grown amorphous nanotubes were then subjected to annealing in a reducing atmosphere at different temperatures while maintaining their amorphicity. The morphological, physicochemical, and electronic properties were then thoroughly evaluated to assess their use in different fields, from energy storage devices to photo‐catalytical applications.