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

Porous tin oxide (SnO 2 ) nanotubes were prepared by using multiwalled carbon nanotubes as templates. The morphology and crystal structure of the SnO 2 nanotubes were characterized by field emission scanning electron microscopy, transmission electron microscopy, and X-ray diffraction. The SnO 2 crystallite size was about 5 to7 nm. The as-prepared porous SnO 2 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 °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 SnO 2 nanotubes was also discussed.