A SIMPLE AND VERSATILE SOL-GEL METHOD FOR THE SYNTHESIS OF NANOCRYSTALLINE SEMICONDUCTING OXIDES FOR GAS SENSORS

摘要

Much interest has been devoted in the literature to the synthesis of nanometric ceramic powders because of the peculiar properties deriving from their high surface-to-bulk ratio. Materials properties and performances in numerous areas of modern science and technologies are in fact critically controlled by particle size, in particular those requiring surface interactions like chemical sensors. Semiconducting oxides can be used as chemoresistive sensors for atmospheric monitoring only when grain size is reduced to the nanometric level. For this application, the use of different oxides is necessary to monitor different pollutants, e.g. indium oxide for ozone or LaFeO3 for NO_x.