ZnO/ZnAl2O4 prepared by calcination of ZnAl layered double hydroxides for ethanol sensing

In this work, ZnO/ZnAl2O4 has been prepared by calcination of ZnAl layered double hydroxides (Zn2Al-LDH), and the resulting products calcined at different temperatures have been characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), and Al-27 solid-state nuclear magnetic resonance (NMR). The gas sensing measurement indicates that the sample calcined at 1000 degrees C shows much higher response to ethanol due to its better crystallinity of ZnAl2O4 than that calcined at 800 or 600 degrees C, respectively. In addition, the sample calcined at 1000 degrees C exhibits fine repeatability and good selectivity for ethanol. It has been demonstrated that the ZnAl2O4 inside the calcined sample acts as a catalyst to accelerate the response and recovery behaviors in ethanol sensing. (C) 2013 Elsevier B.V. All rights reserved.