Ethanol gas sensing properties of nano-crystalline cadmium stannate thick films doped with Pt Original Research Article

The effect of Pt on gas sensing properties of nano-crystalline CdSnO3, a semiconducting oxide with perovskite structure, was studied. CdSnO3 was prepared by solid-state reaction of inorganic reagents 3CdSO4·8H2O, SnCl4·5H2O and NaOH. The thermal analysis was detected by means of thermogravimetric-differential thermal analysis (TG-DTA). XRD was used to confirm the material structure and TEM to depict the crystallite microstructure and the specific surface area was measured by Brunaur–Emmett–Teller (BET) method. Noble metal additive Pt of different concentrations from 0.1 to 2 at.% was incorporated into CdSnO3 by impregnation technique. Conductance responses of the nano-crystalline CdSnO3 thick films were measured by exposing the films to C2H5OH, CO, CH4, C4H10, gasoline and LPG at different operating temperatures. It was found that sensors doped with Pt exhibited good sensitivity and selectivity to the vapor of C2H5OH and the optimum sensitivity is obtained with the sensor doped with 1.5 at.% Pt.