Controlled Synthesis of TiO2 Hierarchical Nanofibre Structures via Electrospinning and Solvothermal Processes: Photocatalytic Activity for Degradation of Methylene Blue

The present article describes a new titanium oxide-based (TiO2) photocatalyst that shows promise for acceleration of dye degradation. A hierarchical TiO2 nanostructure comprising nanorods on-nanofibres has been prepared using a sol-gel route and electrospinning. Calcination of electrospun nanofibre mats was performed in air at 500 °C. The TiO2 nanofibre surface was then exploited as a 'seeding ground' to grow TiO2 nanorods by a solvothermal process in NaOH. The nanofibres had a diameter of approximately 100 nm while the nanorods were evenly distributed on the nanofibre surface with a mean diameter of around 50-80 nm. The hierarchical nanostructure showed enhanced photocatalytic activity when compared to pure TiO2 nanofibres. This improved efficiency in degrading methylene blue through the photocatalytic process was attributed to the larger specific surface area of the TiO2 nanostructures, as well as high surface-to-volume ratio and higher reactive surface resulting in enhanced surface adsorption and interfacial redox reaction.