ABSTRACT
TiO2-SnO2 composite nanocrystalline was prepared by the low temperature hydrothermal method. A new film-type ozone sensor was developed by using TiO2-SnO2 composite nanocrystallines transferred onto an alumina ceramic tube with Au electrodes by dip-coating method. The crystalline phase and microstructure of TiO2-SnO2 nanocrystallines were characterized by X-ray diffraction ( XRD) , field emission scanning electron microscope ( FE-SEM) , energy dispersive X-ray analysis ( EDAX) and ultraviolet-visible spectrometry ( UV-Vis) . The ozone sensitive mechanism and photoelectrochemical properties of TiO2-SnO2 nanocrystallines were analyzed by using ultraviolet-visible spectrometry and electrochemical method. These characteristic tests of ozone sensor were carried out on the traits of sensitive performance, dynamic response, interference and stability under ultraviolet-visible illumination by the XEDWS-60 A type multifunction analyzer in gas sensor static test system. the conclusion demonstrates that when the ozone sensor based on TiO2-SnO2 composite nanocrystalline ( molar ratio of Ti and Sn is 6 ) was under conditions of 40% relative humidity and 25 ℃operating temperature, when ozone concentration was increased from 0. 1 to 1. 8 μg/L, the best linearity of ozone sensor upon ultraviolet illumination and visible illumination were 97 . 5% and 78 . 5%, the dynamic response time was 2 s and 9 s, the recovery time was 5. 5 s and 15 s. This kind of sensor showed good anti-disturbance to the gases, such as CO, NOx , formaldehyde, acetone, butanol and methanol. The response value of ozone sensor was attenuated about 4 . 7%, when ozone sensor was applied continually on the automobile about 12 months, and its normal time was 8. 5 months.