Gas sensing properties of self-assembled ZnO nanotube bundles

Abstract

Large-scale ZnO nanotube bundles were synthesized by a simple solution-based method under mild conditions. The structural and optical properties of the resultant products were characterized using X-ray diffraction, scanning electron microscopy, transmission electron microscopy, nitrogen adsorption–desorption and photoluminescence techniques. The sensor based on the ZnO nanotube bundles exhibited excellent sensing properties against ethanol gas at the operating temperature of 230 °C. The sensitivity of the sensor to 100 ppm ethanol was approximate 25.2 with a rapid response time (about 3 s). It was found that the ZnO nanotube bundle sensor displayed significantly better sensing performances due to a larger surface area and more electron donor related oxygen vacancies in comparison with the ZnO nanorod bundle sensor.