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 27Al solid-state nuclear magnetic resonance (NMR). The gas sensing measurement indicates that the sample calcined at 1000 °C shows much higher response to ethanol due to its better crystallinity of ZnAl2O4 than that calcined at 800 or 600 °C, respectively. In addition, the sample calcined at 1000 °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.