Structure of helical Nb 2 O 5 nanotubes studied by transmission electron microscopy

The structure of Nb 2 O 5 nanotubes was studied by electron diffraction and high‐resolution transmission electron microscopy (HRTEM). The nanotubes were prepared from highly crystalline‐layered K 4 Nb 6 O 17 crystals grown from a KCl flux using the intercalating and exfoliating techniques. Nanotubes have a length of about 200 nm and a diameter of 20 nm. The observed electron diffraction patterns revealed that the nanotubes have a helical structure with the basal plane of (010) and the tube‐axis parallel to the [201] direction. Their basal plane corresponds to the (010) plane of the layered K 4 Nb 6 O 17 crystals. The helical lattice plane was directly observed by a Fourier filtered HRTEM image. Copyright © 2014 John Wiley & Sons, Ltd.