溶胶-凝胶合成NiO-ZnO复合物及其乙醇敏感特性研究

Study on Ethanol Sensing Properties of NiO-ZnO Composite Synthesized by Sol-Gel Mtehod

以Zn(NO3)2.6H2O和Ni(NO3)2.6H2O为原料,采用柠檬酸溶胶-凝胶法合成了NiO-ZnO系列复合物。利用X射线衍射仪(XRD)、扫描电镜(SEM)、透射电镜(TEM)等对系列复合物的物相及形貌进行表征,利用静态配气法对其气敏性能进行测试。研究了煅烧温度对复合物乙醇敏感特性的影响。结果表明,600℃下煅烧得到的NiO-ZnO复合物对乙醇在较低的工作温度125℃下具有良好的敏感性能,如对50 ppm乙醇的灵敏度为29.8,响应和恢复时间很短仅为8 s和14 s,且对于汽油、丙酮、乙醚等其余7种测试气体有较高的选择性,经1个月的稳定性测试该复合物对乙醇敏感特性基本保持不变。

The NiO-ZnO composites were prepared by a citric acid assisted sol-gel method using Zn（NO3 ）2 . 6H2O and Ni（NO3）2 . 6H2O as raw materials. The phase and morphology of the materials were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM） and transmission electron microscopy （TEM）. The gas-seining properties of NiO-ZnO were evaluated via a static volumetric method. The influence of the calcining temperature of the composite on ethanol sensitive characteristic was studied. The results showed that the NiO-ZnO composite obtained by calcined at 600 ℃ exhibited a good response to ethanol at low working temperature of 125 ℃, for example, the response was 29.8 to 50 ppm ethanol, and the response and recovery time was 8 s and 4 s, respectively. At the same time the sensor had an excellent selectivity to other seven kinds of tested gases, such as petrol, acetone, ether, etc. The gas-sensing properties of NiO-ZnO （600 ℃ ） composite to ethanol remained almost unchanged by a month of stability test.