Abstract
Abstract Since Fujishima and Honda discovered the photocatalytic property of TiO2 in 1972, extensive research has been conducted. In this study, nanostructured titania was prepared by a reflux method. Both nanoparticles and nanotubes were obtained by this method. Several experimental parameters were controlled, such as temperature, reaction time and pH value, to better understand the formation mechanism of titania nanotubes and to get the best synthesis condition. In addition, PL and UV-absorption spectra were measured for nanoparticle and nanotube samples. It is seen that the nanotube has an absorption peak at 400nm, different from that of the particle. For the PL measurement, the intensity of nanotubes is stronger than that of particles. In order to improve the conductivity and field emission property, two metal ions, Fe and Nb, were doped into titania nanotubes to make p- and n-type semiconductor, respectively. The absorption edge was shifted to longer wavelength when the doping concentration increases. For pure TiO2 nanotubes field emission properties were not observed. The turn on field, of 0.025mol% Nb and Fe doped TiO2 nanotubes are 23 and 12 V/μm, respectively, with the defined current density at 0.01mA/cm2. The electronic and photonic properties of TiO2 nanotubes are discussed on the basis of nanostructure and doping composition.