Preparation and ethanol gas sensor properties of SnO₂ nanowires

Abstract

Tin oxide nanowires were successful prepared using thermal evaporation method. The crystal structure and surface morphology of the nanowires were characterized by X-ray diffraction, scanning electron microscope and transmission electron microscope. The as-prepared nanowires are rutile single crystal SnO2 structure, with diameter in 50-200nm, and length of 5-15μm, conforming to the gas-liquid-solid growth mechanism. The heater structure gas sensor was prepared using SnO2 nanowires as the gas sensitive material. The gas sensitive performance of the samples was tested in ethanol gas concentration range of 25×10-6-500×10-6. The results show that the best working temperature of the sensor is about 260℃; in the 25×10-6 and 500×10-6 ethanol gas environment, the sensitivity is 7.54 and 111.01 respectively, response time of the sensor is 2-20s, and recovery time is 5-33s;the sensitivity and the gas concentration has a good linear relationship within the measuring range; the sensor has favourable stability with less than 5% repeated measurement error in 7 days.

Keywords

• thermal evaporation
• tin oxide
• nanowire
• gas sensor property