Enhanced low-level acetone detection by zinc/tin bi-metallic oxides nanocomposite with long-term stability

Zinc/tin bi-metallic oxides nanocomposites (ZTNs) were fabricated by a simple hydrothermal process. The characterization of the ZTNs by X-ray diffraction (XRD), field effect scanning electron microscopy (FESEM), and Brunauer–Emmett–Teller (BET) confirmed the formation of a mixture of the ZnO and SnO₂ crystallites in porous nanocomposite with nanosheet morphology. Acetone gas-sensing features of the ZTN sensor (ZTS) were studied at different operating temperatures as a function of low gas concentration from 0.5 to 10 ppm. The ZTS responses were 54.4, 42.3, and 30% toward 10, 2, and 0.5 ppm acetone concentration, respectively, at an optimum operating temperature of 110 °C. Our low-cost device showed the appropriate ability for the acetone gas detection at low level with attractive stability and selectivity, which suggests it as a reliable biomarker sensor in health monitoring. The acetone gas-sensing mechanism of the sensor was analyzed and discussed as well, through the standard thermionic emission model and the gas molecules adsorption/desorption process.