纳米ZnO的制备及其气敏性能

Preparation of Nano-ZnO and Its Gas Sensitivity

通过螯合物分解法、微乳液法、溶胶 凝胶法制备了不同粒径的纳米ZnO粉体。利用X射线衍射仪、透射电镜对材料的形貌、结构进行了表征。结果表明 ,3种ZnO均为六方晶系纤锌矿结构 ,与其它 2种方法比较 ,微乳液法制备的纳米ZnO粒径较小 ,为 2 0nm左右 ,且分布较集中。研究了不同制备方法对材料的气敏性能的影响。在工作温度 335℃时 ,螯合物法ZnO和溶胶 凝胶法ZnO对Cl2 的灵敏度均低于 30 ,且选择性差。而微乳液法ZnO对Cl2 的灵敏度高达 5 12。响应时间不到 5s,恢复时间达数分钟。

The ZnO powders were prepared separately by decomposition of zinc chelate, W/O micromulsion method and sol-gel method and characterized by XRD and TEM. All the ZnO obtained by mentioned methods has hexagonal wurzite structure. The ZnO prepared by micromulsion method was sized in 20 nm, smaller than that obtained by the two other method, but had better dispersity. The ZnO made by micromulsion method had a sensitivity of 512 to Cl 2 at the optimum working temperature 335 ℃. The response time of ZnO made by micromulsion method was 5 s, and the restoration time was several minutes.