Abstract :
SnO2rAl2O3rNb2O5rSiO2 thick-film sensors were fabricated by screen-printing and dipping, and their sensing
characteristics to CH3CN gas were investigated. The oxidation products of CH3CN on the thick film were analyzed by
Fourier transform infrared spectroscopy FTIR.using a heatable gas cell. The IR results showed that the products formed by
oxidation of CH3CN at 3008C on the SnO2rAl2O3rNb2O5 thick film without SiO2 were mainly CO2, H2O, and NH3,
while on the SnO2rAl2O3rNb2O5rSiO2thick film products such as CO2, H2O, N2O, HNO3, and HNO2were observed.
The thick-film devices containing SiO2showed high selectivity and negative sensitivity to CH3CN due to the presence of
nitrogen compounds produced by oxidation of CH3CN. The optimum amount of Nb2O5 and the optimum operating
temperature were 1.0 wt.% and 3008C, respectively. q2000 Elsevier Science B.V. All rights reserved
Keywords :
SnO2-based sensor , FTIR spectra , Dipping of Si C2H5O.4 , Negative sensitivity , Oxidation of CH3CN
