Large aspect ratio titanate nanowire prepared by monodispersed titania submicron sphere via simple wet-chemical reactions

A facile one-step hydrothermal reaction among monodispersed titania submicron spheres and KOH solution was found to result in potassium titanate nanowires with a large aspect ratio. The diameter of these nanowires falls in the range of 50–200 nm and the length ranges from several micrometers to several tens of micrometers. It is found that the reaction temperature, duration, titanium source and the size distribution of titania raw powders have a great impact on the resultant morphology. Monodispersed TiO2 submicron sphere is beneficail for the formation and growth of large-area lamellar potassium titanate and consequently it is in favor of the production of nanowires with a large aspect ratio. The nanowires were analyzed by a range of methods including powder X-ray diffraction (XRD), scanning electron microscope (SEM), high-resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED), energy-dispersive X-ray spectrometer (EDX) and UV/Vis spectrophotometer. UV-absorption study showed that these nanowires are wide-band semiconductors with a band gap 3.4 eV. A formation mechanism is proposed on the basis of the dissolving, growth, thickening and splitting of K2Ti6O13 nanointermediates.