The structure of titanate nanotubes prepared by the hydrothermal
method was identified to be related to the structure
of NaxH2 − xTi2O5·H2O. This was approved by the comparison
of powder X-ray diffraction pattern calculated via the Debye
formula with the experimental data, the comparison of the
Fourier transformation of the model with the experimental
precession electron diffraction pattern and also from the
structure image reconstructed from a series of HRTEM images.
For improving the agreement of the simulated and experimental
X-ray diffraction patterns, it is suggested that the
effect of preferred orientation of nanotubes on the substrate
holder should be considered and accurate atomic positions in
the nanotubes should be determined as well.