Metal Oxide Nanowires for Use in Chemical Sensing Applications

The electrospinning technique was employed to produce nanofiber/nanowire structures of MoO₃ and WO₃, using metal oxide-sol–gel and polymer solution mixtures as precursors. The effect of variation of processing parameters and composition was studied and it was found that the diameter of these novel nanostructures decreases with increasing the sol–gel concentration and reducing the solution flow rate. A case study is presented where WO₃ nanowires are used as NO₂ gas sensing elements and are compared to sol–gel processed films of the same material. The nanowires-based elements make better sensors, as they exhibit improved gas sensitivity, faster response and lower gas detection limit that the sol–gel based elements.