Molybdenum and Tungsten Oxide Nanowires Prepared by Electrospinning Katarzyna M. Sawicka, Mallikarjun Karadge 1 , Pelagia-Irene Gouma 1 Department of Chemistry, Stony Brook University, Stony Brook, NY 11794 1 Department of Materials Science and Engineering, Stony Brook University, Stony Brook, NY 11794 ABSTRACT Tungsten oxide (WO 3 ) and molybdenum oxide (MoO 3 ) nanowires were synthesized through utilizing sol gel and electrospinning methods. Mixtures of metal oxide sol gel and polyvinylpyrrolidone (PVP) in ethanol solution were electrospun and resulted in metal oxide composite nanofiber mats. Precise annealing process removed all organic material, and pure metal oxide single crystal nanowires remained. Both the as-spun nanocomposite mats and the heat-treated nanofiborous materials were characterized using Scanning and Transmission Electron Microscopes. The average diameter of the nanofibers was concluded to be proportional to the flow rate used and inversely proportional to the metal oxide concentration in the solution. INTRODUCTION Metal oxide nanomaterials have been a subject of intense research due to their potential application in many areas that include electronics, photonics, mechanics, and sensing. Tungsten and molybdenum oxide thin films typically obtained by sol gel or ion beam deposition [1,2], electrodeposition [3], R.F. magnetron sputtering, thermal evaporation [4,5], and chemical vapor deposition [6] have been previously studied as conductimetric gas sensors [1,2], and as coatings for smart windows [4-6]. MoO 3 and WO 3 semiconductor sensors based on sol-gel processed thin films were found in our earlier research to be excellent gas sensing materials for the detection of ammonia and NO 2 respectively [1-2]. It is expected that a network of one-dimensional nanofibers will offer a much greater surface area to volume ratio than the thin films previously studied thus enhancing the adsorption rate of gases on these materials, improving sensor sensitivity and response time. Furthermore, the electro chromic properties of MoO 3 and WO 3 nanofibers could be employed in smart textile production, such as military armor. With nanotechnology becoming a vital component to research and industry, electrospinning has become one of the main tools used. The notion of creating nanofibers through electrifying molten solutions was first documented in 1934 [7]. Recently creation of various polymeric nanofibers has been extensively reported with emphasis on the relationship between process parameters, such as viscosity, the net charge density, and the surface tension, on nanofiber size and morphology [8-15]. The controlled directionality of the produced nanofibers has been studied by advancements implemented on the electrospinning set up [16-20]. The large aspect ratio of surface area to volume for electrospun mats, and versatile design offer great potential for many applications like tissue engineering, catalysis, and sensing. Most recently electrospinning EE9.46.1 Mater. Res. Soc. Symp. Proc. Vol. 847 © 2005 Materials Research Society