Keywords: aerosols, CVD, chemical vapour deposition, metal oxide nanoneedles, metal nanoparticles, tungsten oxide, gas sensors, nanotechnology, nanostructures, nanomaterials, n–type semiconductors, ethanol
AA–CVD growth and ethanol sensing properties of pure and metal decorated WO3 nanoneedles
This paper reports the co–deposition, in a single step, of metal nanoparticles and tungsten oxide nanoneedles by aerosol–assisted chemical vapour deposition. The method leads to the growth of WO3 nanoneedles decorated with copper, gold or platinum metal nanoparticles, respectively. Scanning electron microscopy, transmission electron microscopy and energy–dispersive X–ray analysis have been used to investigate the morphology and composition of the different nanostructures grown on Al2O3 substrates. Gas sensors employing the different nanostructures have been fabricated and a preliminary characterisation of their sensing properties to ethanol vapours is shown. Our nanomaterials behave as n–type semiconductors in the presence of ethanol, and those decorated with metal nanoparticles show high stability, high reproducibility, high response and rapid detection of ethanol vapours at moderate operating temperatures (i.e. 250°C).