NANO HIGHLIGHT Nano Jelly Rolls: The Atomic Structure of Vanadium Oxide Nanoparticles

Manufacturing a material with nanometer length dimensions imbues it with special properties coming solely from its small size. This is the basis of nanotechnology [1]. For example, great excitement exists about the properties of hollow carbon nanotubes called buckytubes [2], but can other materials be manufactured into nanotubes and have their properties similarly enhanced? One example is vanadium pentoxide, V2O5. In the bulk the material is useful in applications such as optical switches, chemical sensors, catalysts and solid-state batteries. In the form of nanotubes these properties are further enhanced, but in addition, completely novel applications such as nanoactuators and nonlinear optical limiters are envisaged [3]. A severe limitation to its full implementation in technology is a lack of knowledge of its atomic scale structure in the nanocrystalline form. This is a generic problem with nanostructured materials since conventional crystallographic methods of structure solution don’t work on the nanoscale. The NSF funded NIRT-Structure of Nanocrystals is addressing this need by developing and applying advanced scattering methods to solve the structure of nanoparticles [4]. Earlier we resolved a long-standing controversy about the atomic structure of nanoporous V2O5 xerogel [5] and showed it to be made of flexible layers of edge-shared octahedra. NIRT researchers have now shown [3] that, in the V2O5 nanotube, these layers appear to roll up resulting in the nanotube: a nanometer length-scale jelly roll