Nanoparticle engineering for gas sensor optimisation: improved sol-gel fabricated nanocrystalline SnO2 thick film gas sensor for NO2 detection by calcination, catalytic metal introduction and grinding treatments

The control of the technological steps such as calcination temperature and introduction of catalytic additives are accepted to be key points in the ob taining of improved sol-gel fabricated SnO2 thick film gas sensors with dif ferent sensitivity to NO2 and CO. in this work, after proving that the undo ped material calcined at 1000 degrees C is optimum for NO2 detection, grind ing is added as third technological step for further modification of partic le surface characteristics, allowing to reduce cross-sensitivity to CO. The influence of grinding on the base resistance and on the sensor signals to NO2 and CO is discussed in detail as a function of the structural differenc es of the sensing material. (C) 1999 Elsevier Science S.A. All rights reser ved.