Review—Advent of TiO₂Nanotubes as Supercapacitor Electrode

Design of nano-porous materials for electrodes is a promising approach for enhancing the storage capacity of electrochemical energy storage devices. In recent years, titanium dioxide (TiO 2 ) nanotube arrays have emerged as an auspicious candidate in this category because of its high surface area, porosity, mechanical strength and excellent transport properties in addition to its low cost, non-toxic and environmental friendly nature that are best suited for supercapacitor electrodes. The unique properties such as unidirectional electron transport, chemical and mechanical stability makes it an interesting option for researchers. The recent advancement in electrochemical nanofabrication has paved the way for precise control over the tube geometry and improved the ease in co-deposition of composite constituents. Methods such as doping, plasma treatment, preferential crystal axis growth, hydrogenation and nitridation have been used to enhance the electrochemical capacitance of titania nanotubes. This article reviews the strategic emergence of TiO 2 nanotube as competent electrode material for supercapacitors and its future scope.