Nanostructured CdO-ZnO composite thin films for sensing application

摘要

CdO-ZnO nanocomposites were synthesized by the facile SILAR method. In synthesis, 0.1 M Cd (NO_3)_2 and 0.1 M Zn (NO_3)_2 were used as sources of Cadmium and Zinc ions, respectively. The supersaturated solutions of Cd and Zn ions served as a cationic bath while 0.075 M NaOH as an anionic bath. To synthesize composite samples, the number of dipping is varied as 1:1, 1:2, and 1:3 concerning (CdO-ZnO). The XRD patterns of composite samples exhibit distinct peaks of ZnO and CdO, which clearly indicates the formation of CdO-ZnO nanocomposites in thin film form. The FE-SEM shows interlocked sheets with a thickness varies from ～ 30 nm to 300 nm for composites. EDAX mapping and XPS study, confirms that the obtained nanocomposite is actually composed of CdO and ZnO. The gas sensing behavior of CdO-ZnO is systematically investigated for 4 test gases under different operating temperatures and different gas concentrations. The maximum response of 52.04% is obtained for 24 ppm of Ethanol at a minimum operating temperature of 325 °C.