Preparation of Porous Tin Oxide Nanotubes Using Carbon Nanotubes as Templates and Their Gas-Sensing Properties

Porous tin oxide (SnO2) nanotubes were prepared by using multiwalled carbon nanotubes as templates. The morphology and crystal structure of the SnO2 nanotubes were characterized by field emission scanning electron microscopy, transmission electron microscopy, and X-ray diffraction. The SnO2 crystallite size was about 5 to 7 nm. The as-prepared porous SnO2 nanotubes exhibited a good response and reversibility to some organic gas, such as ethanol and acetone. The sensor responses to 100 ppm ethanol and acetone were 130 and 126, respectively, at a working temperature of 200 degrees C. In addition, the sensors also exhibited a good response to methanol, propanol, 2-propanol, ethyl acetate, and ethyl ether. The relationship between the gas-sensing properties and the microstructure of the as-prepared SnO2 nanotubes was also discussed.