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 °C. 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 °C.