Enhanced gas sensing properties for ethanol of Ag@ZnSnO3 nano-composites

Abstract

Metal semiconductor oxides are widely used in the field of gas sensors in recent years due to the advantages of good gas sensitivity, low raw material cost and facile preparation. To achieve more sensitive, accurate and rapid detection of ethanol gas, tetrakaidecahedral ZnSnO3 nanoparticles were successfully synthesized by means of a facile template-free co-precipitation method. The nano-Ag particles were decorated evenly on the surface of the ZnSnO3 particles with a heat treatment at 250 °C. The as-synthesized products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectrometer (EDS) and X-ray photoelectron spectroscopy (XPS). The results of gas sensing test experiment show that the tetrakaidecahedral ZnSnO3 decorated by nano-Ag (Ag@ZnSnO3) sample has excellent gas sensitivity properties to ethanol at 220 °C. In particular, the composite Ag@ZnSnO3 material gas sensor has a short response time of 2 s and recovery time of 23 s as the nano-Ag modification ratio is 5%. The responsivity of the Ag@ZnSnO3 gas sensor with a modification ratio of 5% to the 500 ppm ethanol is 258 at 220 °C, which is 2.83 times of the pristine ZnSnO3 gas sensor. The minimum limit detection of the sensor to ethanol is 2 ppm. The research in this paper confirms that Ag@ZnSnO3 composite material has potential application prospects in the manufacture of high-performance ethanol sensors.