CO2-SENSING CHARACTERISTICS OF SNO2 ELEMENT MODIFIED BY LA2O3

When an SnO2 element is impregnated with an aqueous solution of metal nitrate or acetate by coating with a brush and calcining at 773 K for 5 h, the element shows sensitivity to ppm-levels of CO2. Among the elements, the La2O3-loaded SnO2 element is found to show promising sensing properties to CO2 in dry air at 673 K, i.e., rather high sensitivity and quick response. The sensing properties depend on the operation temperature and the amount of La2O3 loaded: the respective optima are 673 K and 4.2 wt.%. The sensitivity monotonically increases with the concentration Of CO2 in the range 0-2080 ppm.