Enhanced electrochemical performance of porous Co-doped TiO2 nanomaterials prepared by a solvothermal method

Highly porous nanostructures having large specific surface areas are very desirable for electrochemical supercapacitors to achieve a large energy storage capacity. We synthesized porous Co-doped TiO 2 nanostructures with an average diameter of 450 nm through a simple solvothermal method by using tetrabutyl titanate and cobalt acetate as precursors and polystyrene beads as templates. The optimized 7% Co-doped TiO 2 nanostructures-based supercapacitor electrodes exhibited a specific capacitance of 352 F g -1  at a current density of 0.5 A g −1 while retaining a capacity of 97.2% after 3000 cycles. This excellent electrochemical performance may be ascribed to the synergistic effects originating from conductivity enhancement of TiO 2 through optimized Co-doping and larger specific surface areas rendered by structural porosity, when compared to the undoped TiO 2 samples. Our results suggest that porous Co-doped TiO 2 nanostructures can be explored for potential electrochemical applications.