Porous sol-gel silica film doped with NiO and Au nanocrystals as platform for different kind of gas sensor transducers

Sol-gel silica porous films doped with NiO and Au nanoparticles have been used as platforms for conductometric, optical and surface acoustic wave (SAW) gas sensors. The nanocomposite films showed poor conductometric gas sensing response toward CO, NO2 and H2. On the contrary both optical and SAW gas sensors showed reversible and stable response to CO and H2. Moreover the possibility to selectively recognize H2 and CO is studied exploiting the wavelength dependence of the gas induced optical transmittance variation.