V2O5 Nanotubes Research Articles

Atomic-scale structure of nanocrystals by the atomic pair distribution function technique

The approach of the atomic pair distribution function (PDF) technique to determine the atomic-scale structure of nanocrystalline materials is introduced and illustrated with results of studies on V2O5 nanotubes and clusters of Cs atoms intercalated inside the pores of the zeolite ITQ-4. We find that V2O5 nanotubes are built of double layers of V-O5 and V-O4 units. Inside the channels in ITQ-4 Cs atoms are found to assemble in short-range ordered zigzag chains.

Electronic band structure of scroll-like divanadium pentoxide nanotubes

The atomic models of infinite-long divanadium pentoxide nanotubes with scroll-like morphology are presented and their electronic properties are studied using the tight-binding method. As compared to cylindrical zigzag (n,0) and armchair (n,n)-like V2O5 nanotubes, which are uniformly semi-conducting and have the band gap of about 2.5–2.9 eV, the gap of the scroll-like tubes trends to vanish (up to ∼0.1 eV) depending on the atomic configurations of the tubes and the inter-wall spacing. Relative stability of cylindrical and scroll-like V2O5 nanotubes is discussed.

V2O5 nanofibre sheet actuators.

Vanadium oxides, such as V2O5, are promising for lithium-ion batteries, catalysis, electrochromic devices and sensors. Vanadium oxides were proposed more than a decade ago for another redox-dependent application: the direct conversion of electrical energy to mechanical energy in actuators (artificial muscles). Although related conducting polymer and carbon nanotube actuators have been demonstrated, electromechanical actuators based on vanadium oxides have not be realized. V2O5 nanofibres and nanotubes provide the potential advantages of low-cost synthesis by sol-gel routes and high charging capacity and long cycle life. Here, we demonstrate electromechanical actuation for obtained high modulus V2O5 sheets comprising entangled V2O5 nanofibres. The high surface area of these V2O5 sheets facilitates electrochemical charge injection and intercalation that causes the electromechanical actuation. We show that the V2O5 sheets provide high Young's modulus, high actuator-generated stress, and high actuator stroke at low applied voltage.