Authors: B. Cottam, S. Chyla, R. Menzel, A. Bismarck, M. Shaffer
Affilation: Imperial College London, United Kingdom
Pages: 537 - 537
Keywords: titanium dioxide, nanorods
Finely structured titanium dioxide is a technological material of long-standing importance for many applications including pigments and catalysis. There is growing interest in smaller, truly nano-sized titanium dioxide particles with well-defined crystallinity and a range of geometries from spheres to rods and tubes, that are relevant to applications in composites, photovoltaics, sensors, and catalysis. High aspect ratios, in particular, introduce high surface to volume ratios, network forming abilities, and opportunities to control anisotropic properties. Here we report a number of different synthetic strategies for producing high aspect ratio titanium dioxide nanostructures. Ttitanium dioxide is commonly obtained via hydrolysis of metal alkoxides or halides; however, enhanced control over the reaction can be achieved in non-hydrous conditions. A comparison will be made between nanorods synthesised via hydrolytic and non-hydrolytic routes, using different structure directing agents. Typical products are small, single crystal nanorods of anatase (~ 3 25 nm), although aging reactions under suitable conditions yield single crystal rutile nanorods (15 x 135 nm). The hydrolytic synthesis can be dramatically accelerated when performed on a microfluidic chip, as compared to a conventional bulk reaction. Alternative strategies will also be discussed based on high temperature templating reactions on carbon nanotubes, and hydrothermal treatment in strongly basic conditions. Preliminary composite and device application data will be provided.