Local structure study of vanadium pentoxide 1D-nanostructures

Vanadium pentoxide (V₂O₅·nH₂O) 1D-nanostructures as nanowires and nanorods have been obtained by decomposition of vanadium peroxide in hydrothermal conditions. Electron microscopy, Raman spectroscopy, and X-ray absorption spectroscopy (XAS) were employed to characterize the morphology and the local structure of as-obtained samples. Scanning transmission electron microscopy (STEM) revealed that the diameter of the nanowires and nanorods were found to be 10–20 and 30–40 nm, respectively. The results demonstrated that a combination of Raman and XAS techniques allowed the accurate characterization of the local structure of V₂O₅ 1D-nanostructures which are related to different morphologies. Analyses of X-ray absorption near-edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) spectra reveals that the local structure of V in the as-obtained samples is similar to the bulk V₂O₅ (in orthorhombic phase), except for a higher degree of local symmetry within the structure of the VO₅ square pyramid. Additionally, the nanostructures prepared by this technique present a single crystalline nature and could emit visible light at room temperature which is related to the local order of V atoms of the studied samples.