Electrospun TiO₂–rGO Composite Nanofibers with Ordered Mesopores by Molecular Level Assembly: A High Performance Anode Material for Lithium-Ion Batteries

The authors report a novel strategy to fabricate electrospun anatase TiO₂–rGO composite nanofibers with 3D cubic ordered mesoporosity. Such synthesis route not only ensures molecular level composite formation between rGO and TiO₂ but also retains the rGO content and orders mesostructure after calcination of the nascent fiber at an optimum condition that only removes the surfactant and polymer. Transmission electron microscopic and low angle X-ray diffraction studies confirm the presence of ordered mesoporosity within the nanofibers. Raman and X-ray photoelectron spectroscopy studies reveal the molecular level composite formation between rGO and TiO₂ with chemical bonding. This composite nanofiber with high surface area (155 m² g^–1) is tested as an anode material in lithium-ion batteries. Intrinsically formed TiO₂–rGO composite structural features with channel like interconnected 3D order mesopores within 1D fibrous morphology help in achieving 94% of the theoretical capacity (335 mAh g^–1 for one electron transfer) at a current density of 16.75 mA g^–1, the highest reported so far. It shows specific capacity of 212 and 168 mAh g^–1 even at moderately high current densities of 335 and 838 mA g^–1, respectively. Moreover, 85.3% of capacity retains after 500 continuous discharge/charge cycles at 335 mA g^–1.