MoO 3- x -deposited TiO 2 nanotubes for stable and high-capacitance supercapacitor electrodes.

Here we report the supercapacitive properties of a novel MoO 3- x /TiO 2 nanotube composite prepared by a facile galvanostatic deposition technique and subsequently thermal treatment in an argon atmosphere between 350 °C and 550 °C. X-ray diffraction and X-ray photoelectron spectroscopy confirm the existence of MoO 3- x . The MoO 3- x /TiO 2 electrode prepared at 550 °C exhibits a high specific capacitance of 23.69 mF cm -2 at a scan rate of 10 mV s -1 and good cycling stability with capacitance retention of 86.6% after 1000 cycles in 1 M Na 2 SO 4 aqueous solution. Our study reveals a feasible method for the fabrication of TiO 2 nanotubes modified with electroactive MoO 3- x as high-performance electrode materials for supercapacitors.