摘要
Titanium dioxide nanotubes were prepared by refluxing TiO 2 in 10 M NaOH at 200 °C for 12 h. The light absorption edge was slightly shifted to a longer wavelength when 0.025 mol % of iron was incorporated to TiO 2 nanotubes. A turn-on field at 12 V/μm and a maximum current density of 12 mA/ cm 2 at 19 V/μm was observed for the Fe-doped but not for pure TiO 2 . The field emission behavior can be correlated with the geometry and electronic states of the nanotubes. © 2010 American Institute of Physics.