ZnO/PPy异质纳米复合材料的制备、表征及其气敏特性

室温下, 采用原位聚合法, 以吡咯(PY)为单体, 氯化铁(FeCl₃·6H₂O)为氧化剂, 在塑料基片上聚合生长了聚吡咯(PPy)纳米微球. 然后在聚吡咯基片上生长ZnO种子, 将表面种有ZnO种子的PPy元件置于六次甲基四胺与硝酸锌的混合溶液中, 90 ℃水浴中, 在PPy微球上生长了ZnO纳米棒, 合成了PPy/ZnO异质纳米复合材料. 分别通过X射线衍射仪(XRD)和场发射扫描电镜(FESEM)对PPy/ZnO异质纳米复合材料的结构和形貌进行了表征. 制备了塑料基的PPy/ZnO异质纳米复合材料气体传感器, 在室温下, 对10×10^-6-150×10^-6 (体积分数)浓度范围的氨气进行了气敏测试, PPy/ZnO气敏元件对氨气响应的灵敏度基本呈线性关系, 且对甲醇、丙酮、甲苯等有机气体表现出很好的选择性. 最后, 对PPy/ZnO异质纳米复合材料的形成机理进行了简要分析.

Synthesis and Characterization of ZnO/PPy Hetero-Nanocomposites and Their Gas Sensing Properties

Pyrrole (Py) was oxidized by ferric(III) chloride solution in water for the synthesis of polypyrrole (PPy) nanoparticles on the substrate slide by in-situ polymerization at room temperature. Zinc oxide nanorods grew on the PPy nanoparticles when in a water bath at 90 ℃. ZnO/PPy hetero-nanocomposites were obtained by a hydrothermal method and characterized using X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). Gas sensors were fabricated based on the ZnO/PPy hetero-nanocomposites to detect ammonia at room temperature. The gas sensing properties of these hetero-nanocomposites were measured in the concentration range of 10×10^-6-150×10^-6 (volume fraction). The relationship of the sensitivity of the sensors to the ammonia concentration showed linearity. The gas sensor based on ZnO/PPy heteronanocomposites showed good selectivity to ammonia when in the presence of interfering gases such as methanol, acetone, and toluene. The formation mechanism of the ZnO/PPy hetero-nanocomposites was briefly analyzed.