Gas sensing properties of tin dioxide coated onto multi-walled carbon nanotubes

A compound material of multi-walled carbon nanotubes (MWNTs) coated with SnO2 was synthesized at ambient conditions. The Raman spectra, X-ray diffraction (XRD) and transmission electron microscopy (TEM) results confirmed that the existence of SnO2 nanoparticles were on the outside of the MWNTs. The gas sensing properties of the material were studied. It was found that the sensor exhibited nice sensing responses to liquefied petroleum gas (LPG) and ethanol gas (C2H5OH) and a fast response and recovery within seconds. Furthermore, the gas sensor responses increased linearly with the increment of the gas concentrations of LPG and ethanol.