Hydrothermal synthesis of Ag doped ZnO/CeO2 nanocomposites and its application in ethanol sensing

ZnO/CeO2 and Ag/ZnO/CeO2 nanocomposites were successfully synthesized via the hydrothermal method, and then characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy dispersive spectrometer (EDS). The results showed that Ag/ZnO/CeO2 nanoparticles with a size of about 54 nm. The gas sensors based on the as-prepared nanocomposites were fabricated and the ethanol sensing properties were investigated. Comparing with ZnO/CeO2 nanocomposites, Ag/ZnO/CeO2 nanocomposites displayed higher response and quicker response/recovery time. At the optimum operating temperature (362℃), the response value, response and recovery time for 100 ppm ethanol were 6.6, 78 s and 64 s, respectively. Moreover, this sensor has excellent stability and good selectivity for ethanol. In addition, the gas sensing mechanism has also been discussed.