Structural and spectroscopic properties of vanadium dioxide VO2(B) nanofibers

Vanadium dioxide VO 2 (B) nanofibers with typical diameters of about 20–200 nm and lengths up to several microns were prepared via hydrothermal synthesis. The as-prepared VO 2 (B) nanofibers crystallized in a monoclinic structure (space group C2/m ) with unit cell parameters a = 12.0717 Å, b = 3.6949 Å, c = 6.4226 Å, and β = 106.9986°, and elongated along the < 001 > direction. The optical band gap energy of the VO 2 (B) nanofibers was estimated to be about 1.8 eV based on the UV-visible absorption. The VO 2 (B) nanofibers had six diagnostic infrared absorptions at about 1032, 1012, 982, 900, 724, and 660 cm − 1 , representing a clear signature for probing VO 2 (B) materials. The VO 2 (B) nanofibers were nearly Raman inactive at room temperature due to the strong electron-phonon interaction. The thermal conductivity of the VO 2 (B) nanofibers was calculated to be approximately 1.06 W/(m∙K) at room temperature. The distinctive structural and physical properties of the VO₂(B) nanofibers may open up new possibilities for both fundamental research and technological applications.