Temperature dependent behavior of single walled MoO3 nanotubes: A Raman spectroscopy study

In this work we studied the thermal stability of single walled MoO3 nanotubes using Raman spectroscopy technique. By increasing the thermal treatment temperature we observed at about 210 °C that the Raman spectrum characteristic of single walled MoO3 nanotubes changes and the new spectrum is identified to the MoO3 bulk orthorhombic phase (α-MoO3). In situ Raman measurements as a function of temperature increase confirm the collapse of the nanotube structure at about 210 °C. Scanning electron microscopy images confirm the morphology changes in the single walled MoO3 nanotubes for samples treated at different temperatures.