Nanocrystalline Vanadium Pentoxide Xerogel Properties and Hydrogen Sensing

Abstract

Highly oriented nanocrystalline, V2O5,nH2O, film was used as a gas sensor. The thin film was deposited on a glass substrate via the sol gel technique. The size of the nanocrystals was found to be 7 nm applying x‐ray diffraction. The electrical resistance of the film was measured successively twice at a fixed temperature of 338 K during alternating heating/cooling process. It is found that the hydrogen maximum response sensing properties reaches 790 times for 100% hydrogen relative to normal air ambient atmospheric conditions. The very high hydrogen sensitivity at such a low operating temperature indicates that the applied procedure is most effective in sensing different hydrogen/air concentration. The obtained results suggest also that the sensor material do release the adsorbed hydrogen during heating up to 453 K, while the material readsorbs the gas while it is being cooled to room temperature. Additionally it may be suggested that this material can act as hydrogen storage as well during the cooling process.