Hydrothermal synthesis of VO ₂ (A) nanobelts and their phase transition and optical switching properties

Abstract

VO2(A) nanobelts are successfully synthesised through a facile hydrothermal approach using peroxovanadium (V) complexes and green solvent (ethanol) as the reducing agent without using any surfactants or templates. The as-obtained products were characterised by X-ray photoelectron spectroscopy, X-ray powder diffraction, scanning electron microscopy and transmission electron microscopy. The as-obtained VO2(A) nanobelts are with typical lengths up to several tens of micrometres, widths about 180 nm and thicknesses about 45 nm on average. The phase transition properties of VO2(A) was investigated by differential scanning calorimetry, indicating that it exhibits a strong phase transition at around 160.9°C. Furthermore, the optical switching properties of VO2(A) were first studied by the variable-temperature infrared spectra to the best of author's knowledge, and it was found that VO2(A) nanobelts could be used as the optical switch at different vibratory absorption bands.