Oxide Nanowires for Chemical Sensing

Abstract

With the recent terrorist attacks in Paris and the continued use of IED’s employing TATP for delivering these threats, there is a real need for explosives detection at trace levels. This work describes the fabrication and characterization of metal oxide nanowires used as catalysts for the detection of energetic materials at trace levels. Recently, several oxide nanowires, based on zinc oxide and copper oxide, have been incorporated into our solid-state gas sensors as catalysts. These nanowire catalysts produced a dramatic increase in sensor response with improved selectivity for threat molecules of interest. The improved responses were attributed to a large increase in surface area available for catalyst/analyte interaction. Zinc oxide and copper oxide nanowires were grown by hydrothermal and controlled oxidation reactions, and were characterized using XRD, XPS and SEM to determine extent of crystallinity, oxidation state and morphology. Results indicated that energetic materials such as TATP and 2-6 DNT could be detected at the part per billion level using these nanowire catalysts. Other oxide nanowires are being considered as catalysts for the detection of explosives and are discussed as well.