Nickel Doped WO3 Nanoneedles Deposited by a Single Step AACVD for Gas Sensing Applications

One-step Aerosol Assisted Chemical Vapour Deposition (AACVD) method was used for the first time to grow WO3 nanoneedles (NNs) decorated with NiO metal nanoparticles (NPs) at lower (380 °C) deposition temperature. This co-deposition method is demonstrated to be an effective route to incorporate metal NPs into nanostructured materials. A layer of needle-like tungsten oxide film was deposited directly onto transducer alumina substrates from W(CO)6 and Ni(acac)2 precursors. Moreover, the systematic growth study of WO3 NNs + metal NPs allowed the identification of the parameters required for the formation of nanostructured sensing materials having different metal precursor concentration in a range of 2.5 to 15 mg The results show variations in the sensing properties according to the metal precursor concentration. Improved sensing, to some reducing gases, such as EtOH, H2S and NH3 are observed at 200 °C with lower doped tungsten oxide films, whereas higher doped tungsten oxide has shown no response.