Nanoscale single-crystal vanadium oxides with layered structure by electrospinning and hydrothermal methods

The application of electrospinning technique in hydrothermally producing single-crystal vanadium oxide nanorods is described. Vanadium oxide nanorods with a width of less than 100 nm have been formed at the sites of the electrospun composite fibers which themselves lack a crystalline structure. Lithium cations can be incorporated into the compounds by changing the aqueous solution during the hydrothermal process. X-ray powder diffraction indicates that both nanorods have a lamellar structure, with the interlayer distance in lithium vanadium oxide being shorter than in the vanadium oxide. Each nanorod exhibits single-crystal electron diffraction pattern. The morphology is controlled by the electrospinning process as shown by TEM and SEM studies. The vanadium oxidation state in the lithium vanadium oxide nanorods is + 4.75, as determined by both chemical analysis and magnetic measurements. The electrochemical capability is discussed together with the structural and composition study.