Sol-gel template synthesis and characterization of VO ₂ nanotube arrays

In this paper, we report on the obtention of highly ordered VO ₂ nanotube arrays synthesized by the simple sol-gel template method. Techniques of transmission electron microscopy, X-ray powder diffraction, X-ray photoelectron spectroscopy, Raman spectroscopy were used to characterize the morphology and structure of the as-synthesized nanotube arrays. It is found that the size of the as-obtained nanotubes has the dimension of 180-220 nm in outer diameter, 110-140 nm in inner diameter and up to 10 μm in length. The results show that as-synthesized sample is assigned to VO ₂ (B) phase in expected V/O ratio with V existing in the +4 oxidation state.