掺铝ZnO纳米粉的制备与气敏特性研究

用可溶性无机盐法(ISG法)制备掺杂Al^3 的ZnO纳米气敏材料，用D／Max0-rB型X-射线粉末衍射仪研究纳米晶的结构。结果表明制备的掺铝ZnO纳米材料属于六方晶系，纤锌矿结构。用Seherrer公式计算得ZnO和掺铝ZnO的平均晶粒分别为40nm和35nm。用掺铝的ZnO纳米粉做成气敏元件，测试了不同铝含量的纳米材料在不同浓度的乙醇气体和氢气下的敏感特性。结果表明随着气体浓度的增加，灵敏度逐渐上升；随着Al含量的减少，材料气敏灵敏性逐渐增强。当铝含量为Al／ZnO=O．5％(mol)时，对O．2％的乙醇气体的灵敏度最大可达到127。并讨论了纳米材料对敏感气体的物理吸附和化学吸附以及纳米氧化物的气敏机理。

Investigation on Gas Sensing Properties of Nanometer ZnO Doped with Al3+ Prepared by ISG Method

Nanometer ZnO doped with Al 3+ was prepared by ISG method,and the structure was studied by XRD medhod.The Nanocrystalline ZnO belongs to Hexagonal System.The gas sensors were prepared by nano-ZnO doped with Al 3+,and the gas sensing properties were investigated towards different concentration of C 2H 5OH and H 2 gases.Results show that the gas sensitivity increases with the increase of gas concentration,and decreased with doping of Al 3+.A composition of 0.5mol% Al-ZnO sensor shows a maximum sensitivity of 127 towards 2000ppm of C 2H 5OH.The physical adsorption and chemical adsorption were discussed and the gas senging mechanism was also studied.