XRD spectra and TEM image of as-grown TiO2 nanotubes. (a) XRD spectra of as-grown TiO2 nanotubes with different diameters and (b) TEM image taken from an as-grown nanotube with the diameter of 100 nm. The inset also shows the corresponding diffraction pattern.
Lan et al. Nanoscale Research Letters 2013 8:150 doi:10.1186/1556-276X-8-150