| Nano-materials have attracted much attention due to their novel physical and chemical properties which are different from their corresponding bulk materials and have potential technology applications in the fields of microelectronic devices, chemical and biological sensors, light-emitting, displays, catalysis, and energy conversion and storage devices as reported in literatures. ZnO and SnO2 with the large band gap of 3.37 eV and 3.65 eV, respectively, and highly achievable carrier concentration are suitable for application as the gas sensors, transparent electrodes, and other optoelectronic devices. Recently, much effort has been dedicated to the morphology-controllable synthesis of ZnO, SnO2 nanostructures and prototype nanodevices design and demonstration in some areas.In this work, the study is mainly focused on the synthesis and characterization of ZnO and SnO2 nanostructures and gas sensing applications. A hydrothermal method has been developed for the preparation of the ZnO nanorods nanoarrays, nanoflowes and nanosheets, SnO2 hollow spheres. The morphologies, structure and compositions of the nanostructures have been characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), photoluminescence (PL) and transmission electron microscopy (TEM) techniques. Based on the measured PL spectra of the ZnO nanostructures with the peony-like and lotus flower-like morphologies the density of defects in these nanostructures has been studied. A simple gas sensor was fabricated by dispersing the as-prepared SnO2 hollow spheres between two gold electrodes on a ceramic tube in order to investigate the gas sensors properties of the SnO2 nanostructures in detail. The results showed that the gas sensor of the SnO2 hollow spheres exhibited good sensitivity to ethanol, as well as good responsibility, low detection limit and short response/recovery times.
|
PDF Full Text Request