不同合成方法对SnO2型气敏元件响应及恢复时间的影响

通过对不同制备方法所得ＳｎＯ２粉体而制成的气敏元件在低温时对ＣＯ气体响应及恢复时间的比较与研究，得出采用超临界流体干燥法可以制得一种在低温时能够快速响应及恢复的超细二氧化锡粉体，其中粉体粒度的降低可明显缩短元件的响应时间，而恢复时间则主要扩散效应的影响，低温下元件能够快速响应及恢复正是需要粉体具有适宜的孔分布。同时，本文还研究了制备胶体是ｐＨ值对元件响应及恢复时间的影响作用。

Effects of Different Preparation Methods on the Response and Reversion Time of SnO_2 Sensor

A Kind of ultrafine SnO_2 powdercapable of responsing and reversing quickly at lowtemperature was obtained by a sol-gel methodfollowed by the supercritical fluid drying technique.Conclusions were drawn on the basis of thecomparison of different sensor detecting CO at lowtemperatures.The results showed decreasing ofparticle size of the powder could shorten responsetime of the sensor greatly,and the short reversiontime was mainly controlled by the diffusion effect.Atlow temperatures,powders needed a suitable porevolume distribution ensure the fast response andreversion time of the sensor,especially the latter.Furthermore,effects of pH of the preparing gelationwere also discussed in this paper.