Novel gas sensing materials of ZnO-SnO2 nanocomposites were developed using controlled co-precipitation and their sensitivity and selectivity were tested by the detection of environmentally toxic gases. Through manipulating the reaction conditions, such as the Sn/Zn cation ratio, metal salt total concentration, precipitation pH and aging time etc., the nanocrystalline composites with chemical homogeneity and superior thermal stability were successfully prepared and the optimized synthesis parameters have been established. The results showed that these nanocomposites exhibited high sensitivity and selectivity for the detection of CO and NO2, and the sensitivity was dependent on the composition of nanocomposites, calcination and operating temperatures. The sensing performance was greatly enhanced by the introduction of a small amount of Cd or Al2O3 oxide coatings. The gas sensing mechanism of the nanocomposites was also discussed by temperature-programmed desorption (TPD) studies.
|Number of pages||6|
|Journal||Chinese Journal of Inorganic Chemistry|
|State||Published - 1 Aug 2005|
- CO and NO
- Gas sensing properties