CO2 responses based on pure and doped CeO2 nano-pellets

In the present work, the study of semiconducting pure and Gd-doped cerium oxide (CeO2) nanostructures with application to gas sensors is addressed. Nanostructured powders were prepared by means of the co-precipitation technique. The powder has been examined using X-ray diffraction, transmission electron microscope and Raman spectroscopy to estimate the effect of Gd-doping on the properties of ceria. The particle size has been decreased by doping which indicates that the growth restriction rule of Gd in the ceria matrix. Also, a small shift in the peak position accompanied with more broadening in Raman analysis. Finally, the gas response of all powders has been tested for CO2 gas in temperature range from 200 to 400 °C. The Gd-doped CeO2 gas sensor has better sensitivity, good stability and lower operating temperature, with a detection fixed concentration of 800 ppm CO2 gas. The powder sensitivity was found to be maximum at 250 °C for Gd-doped ceria where the pure powder maximum response is predicted to be beyond 400 °C.