Surface engineering of self-assembled TiO2 nanotube arrays: A practical route towards energy storage applications

Here, we present a facile route to establish and control a net negative charge on the surface of TiO2 nanotube as an enabling platform to achieve extraordinary capacitive behavior compared to conventional electric double layer capacitors. The engineering of the surface electrical properties of TiO2 nanotube resulted in an overall improvement in electrochemical performance which is beneficial in a range of applications including wearable light weight electronic devices and energy storage applications. The maximum aerial capacitance of 1.6 mF cm-2 obtained here along with good capacitance retention of 97% after 1000 cycles demonstrate promising properties of these structures for applications in energy storage area.