Abstract
In this work, we describe the synthesis and electrochemical properties of nitridated hierarchical TiO2 nanotubes as an electrode for supercapacitors. The hierarchical TiO2 nanostructures are formed by a controlled layer-by-layer TiO2 nanoparticle decoration on self-organized spaced TiO2 nanotubes. These structures are then annealed in a NH3 atmosphere at elevated temperature to convert the material to a nitride structure - this drastically enhances their electron-transport properties. The areal capacitance of hierarchical structures can be tuned by changing the number of decorated TiO2 nanoparticle layers. The capacitance enhancement of the hierarchical structures reaches a maximum when the surface area through nanoparticle deposition is highest and the conductivity via nitridation is optimized.