Hydrothermal Synthesis of TiO₂ Nanowires-Reduced Graphene Oxide Nanocomposite to Enhance Electrochemical Performance in Supercapacitor

In this paper, uniform TiO₂ nanowires (TiO₂ NWs) on reduced graphene oxide (RGO) nanosheets were successfully synthesized by a simple and low-cost hydrothermal method. The high capacitance (202.5 F⋅g⁻¹ at 1 A⋅g⁻¹) and excellent cyclic stability (81.9% capacity retention after 5000 cycles) were achieved for TiO₂ NWs-RGO nanocomposite as supercapacitor electrode. The excellent electrochemical performance is due to the synergistic effect of one-dimensional TiO₂ NWs with chemical stability and RGO with excellent conductivity. Moreover, TiO₂ NWs can effectively avoid agglomeration, shorten the ion diffusion length and greatly facilitate the charge transfer both at the contact interfaces and within the electrode materials during the electrochemical process. A symmetric supercapacitor was successfully assembled using the TiO₂ NWs-RGO nanocomposite. It possesses a remarkable performance with a specific capacitance of 45.7 F⋅g⁻¹, an energy density of 9.08 Wh⋅kg⁻¹ at a power density of 598 W⋅kg⁻¹ _.