Isopropanol sensing properties of coral-like ZnO-CdO composites by flash preparation via self-sustained decomposition of metalorganic complexes

The coral-like ZnO-CdO composites with the 3D hierarchical porous structure were prepared in a facileflash from self- sustained decomposition of a metal- organic complex. The phases and the morphologiesof the resulting materials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectrum (XPS), respectively. The results showed that the ZnCd composites have a coral- like shape with a size of tens of micrometersand exhibit the hierarchically porous morphology, in which the walls of the macropores contain smallermesopores. The 3D hierarchical architecture consisted of nanoparticles. The gas-sensing characteristicsof the resulted porous ZnO-CdO composites for isopropanol were investigated. Indirect- heating sensorsusing porous ZnO-CdO composites as sensitive materials were fabricated on an alumina tube with Auelectrodes and platinum wires. All measurements were performed at several operating temperaturesfrom 175 to 315 degrees C. Good gas-sensing performances to isopropanol have been found for the preparedsample of porous ZnO-CdO composite with a content of 10 at% CdO (ZnCd10). It is shown that the sensorexhibits the highest gas response and selectivity at the operating temperature of 248 degrees C, making thempromising candidates as practical detectors for isopropanol. (C) 2014 Elsevier B.V. All rights reserved.