Carbon dioxide gas sensing behavior of nanostructured GdCoO3 prepared by a solution-polymerization method

Abstract In this work, nanostructured GdCoO 3 powders were prepared by an aqueous solution-polymerization method using cobalt and gadolinium nitrates, and a mixture of polyvinyl alcohol and polyvinyl pyrrolidone. By X-ray powder diffraction GdCoO 3 was obtained at 650 °C in air. The microstructure of the powders calcined from 610 to 650 °C was analyzed by SEM and TEM; from these results, the typical morphology corresponds to nanostructured laminas. An increase in the inner porosity while increasing the calcination temperature was also observed. The gas sensing characterization was performed at 400 °C, revealing times of response of approximately 10 s in both oxygen and carbon dioxide. The resistance variations were 26 and 4 Ω, respectively. The ability of nanostructured GdCoO 3 to detect changes in the concentration of O 2 and CO 2 was studied. In CO 2 , unique curves were obtained for each gas concentration; however, the results registered in O 2 revealed a lower performance.