CO2-sensing characteristics of SnO2 element modified by La2O3

Abstract When an SnO 2 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 CO 2 . Among the elements, the La 2 O 3 -loaded SnO 2 element is found to show promising sensing properties to CO 2 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 La 2 O 3 loaded: the respective optima are 673 K and 4.2 wt.%. The sensitivity monotonically increases with the concentration of CO 2 in the range 0–2080 ppm.