Nano-urchin:: The formation and structure of high-density spherical clusters of vanadium oxide nanotubes

We report the observation of urchin-like nanostructures consisting of high-density spherical nanotube radial arrays of vanadium oxide nanocomposite, successfully synthesized by a simple chemical route using an ethanolic solution of vanadium tri-isopropoxide and alkylamine hexadecylamine for 7 days at 180 C. The results show that the growth process of the nano-urchin occurs in stages, starting with a radial self-organized arrangement of lamina followed by the rolling of the lamina into nanotubes. The longest nanotubes are measured to be several micrometers in length with diameters of similar to 120 nm and hollow centers typically measured to be similar to 75 nm. The nano-urchin have an estimated density of nanotubes of similar to 40 sr(-1). The tube walls comprise layers of vanadium oxide with the organic surfactant intercalated between atomic layers. The interlayer distance is measured to be 2.9 +/- 0.1 nm, and electron diffraction identified the vanadate phase in the VOx nanocomposite as orthorhombic V2O5. These nanostructures may be used as three-dimensional composite materials and as supports for other materials.