Design and synthesis of 'single-crystal-like' C-doped TiO₂ nanorods for high-performance supercapacitors

Although TiO₂ is widely used as a promising electrode material for supercapacitors, its potential application suffers from a critical limitation due to its poor electrical conductivity and low rate capability. Here, we report a cost-effective hydrothermal strategy to design and construct a novel 'single-crystal-like' C-doped TiO₂ electrode material. The as-synthesized electrode material combines the advantages of TiO₂, 'single-crystal-like' features and carbon doping, considerably improving the electrical conductivity of TiO₂. The electrochemical measurements demonstrate that the C-doped TiO₂ material presents an excellent specific capacitance (449.8 F g^-1 at 1 A g^-1), which approaches six times more than the value (77.3 F g^-1 at 1 A g^-1) of P25 electrodes, and far beyond the value of many previously reported TiO₂ electrodes. Therefore, this work explores a new method to design high performance electrochemical TiO₂ electrode materials by incorporating other dopants into the TiO₂ lattice.