The catalytic effects of the Mg2+-doping on the ethanol-sensing properties of Cd2Sb2O6.8

In this paper, the ultramicro powders of the solid solution (Cd1−xMgx)2Sb2O6.8, with defect pyrochlore structure, were prepared by a chemical cocoprecipitation method. The phase constituents of the powders were characterized by X-ray diffraction (XRD), and the results revealed that the substitutional solid solutions formed when 0≤x<0.20, and that Mg2+-addition could inhibit the growth of the crystalline grains of the product powders during firing treatment process. The influences of Mg2+-addition on ethanol-sensing properties of the system were also investigated. It was found that Mg2+-doping greatly improves the sensitivity, selectivity, stability, response and recovery characteristics of the material to ethanol, and decreases the operating temperature from 330 to 250°C. All of these effects might due to the catalytic characteristics of Mg2+-doping.