Enhancement of the isopropanol gas sensing performance of SnO2/ZnO core/shell nanocomposites
Pure SnO2, ZnO nanoparticles, and a SnO2/ZnO core/shell nanocomposite (NC) were prepared via a sol gel technique. The structure and morphology of the obtained materials were characterized by X ray diffraction (XRD) micro Raman spectroscopy, high resolution transmission electron microscopy (HRTEM) and scanning electron microscopy (SEM) The results showed that highly crystalline materials were formed, and the resulting composites exhibited core/shell structure with a size of 30 nm, whereas the fabricated films exhibited porous morphology. The gas sensing performance of the SnO2, ZnO nanoparticles, and the SnO2/ZnO NC films was investigated for different volatile organic compound (VOC) vapors in the temperature range from 150 to 350 degC. The gas sensing results confirmed that the SnO2/ZnO NC film shows a high selectivity, sensitivity, good stability, and fast response time towards isopropanol at the optimum operating temperature of 300 degC.