标题: | 金触媒修饰锌掺杂二氧化锡奈米棒簇之合成及其低温气体感测应用 Synthesis of Au catalysts modified Zn-doped SnO2 nanorod clusters for low-temperature gas sensing applications |
作者: | 黄洁翎 Huang, Jie-Ling 陈军华 Chen, Chun-Hua 材料科学与工程学系所 |
关键字: | 锌;二氧化锡;奈米粒子;气体感测器;Zn;SnO2;nanoparticle;gas sensor |
公开日期: | 2013 |
摘要: | 本研究主要探讨新颖锌掺杂二氧化锡奈米结构之合成、金奈米粒子表面修饰、及其于一氧化碳气体感测应用。藉由水热法合成参数之调控,以及金奈米粒子修饰技术之选择,成功合成高气感灵敏度金奈米粒子触媒表面修饰之锌掺杂二氧化锡棒簇结构(Nanorod clusters)。 在锌掺杂二氧化锡奈米棒簇结构设计与合成方面,调控锌锡离子比例,除了可以从缺陷化学的角度来最佳化气感灵敏度之外,亦能有效改变奈米棒簇之形貌与尺寸。透过电子显微镜观察,此奈米棒簇结构具有大量且复杂之海胆状阶层式三维立体结构,比表面积极高,有利于气体之扩散及吸脱附反应,奈米棒直径约为20~30 nm,接近气感材料之理想尺寸。为了强化奈米棒簇之气体感测效能,利用单步骤及双步骤合成法,成功获得金奈米粒子修饰之锌掺杂二氧化锡奈米棒簇结构。并发现合成材料回收方法(加热干燥或离心),亦将造成金奈米粒子沉积数量及分散性之差异。 一氧化碳感测结果发现,离心法之金奈米粒子均匀分散在二氧化锡奈米棒簇结构上,感测效果在本研究中最为显着,其灵敏度、响应速率最佳,且工作温度相对较低。此优异特性主要可归因于离心法在相对低温下,可有效地将金奈米粒子良好散布于锌掺杂二氧化锡奈米棒之上,使感测材料可以在较低工作温度下,促进大量气体分子解离。由以上成果可知金奈米粒子修饰之锌掺杂二氧化锡奈米棒簇结构是一非常具有潜力之低温型气体感测材料。 In the thesis, we mainly described the synthesis of novel Zn-doped SnO2 nanostructures, the surface decoration with tiny Au nanoparticles (NPs), and the CO gas sensing applications. With precisely controlled hydrothermal processes and unique Au decoration techniques, a series of highly CO-sensitive catalytic Au NPs decorated Zn-doped SnO2 nanorod clusters were successfully synthesized. Regarding the structural design and syntheis, doping of Zn into the SnO2 lattices is evidenced as a workable strategy not only for optimizing the CO sensitivity from the view point of defect chemistry, but for effectively varying the morphology and size of the prepared SnO2 nanorod clusters. From the observation using electron microscopes, the formed Zn-doped SnO2 nanorod clusters possess excellent urchin-like hierarchical nanostructures with an extremely high surface to volume ratio, which providing a great amount of channels for gas diffusion and large area for gas absorption. In addition, the diameter of each single nanorod is very close to the expected ideal size of nanosensors. For further enhancing the sensing performance, Au NPs synthesized by a one-step or two-step method successfully decorate the Zn-doped SnO2 nanorod clusters. It was also foud that differnt sample collecting techniques (a boiling or centrifugal method) would lead significant difference in the amount and dispersion of the Au NPs. From the analyses of CO sensing performance, remarkable response and recovery features with a highest sensitivity was found at a relatively low working tempeature for the Au NPs decorated Zn-doped SnO2 nanorod clusters prepared by a two-step hydrothermal method and collected by centrifugation. The structural investigations clearly evidence that the well-despersed Au NPs play as a very critical role for providing a great amount of catalytic sites for targeting gas. The present results conclude that the Au NPs decorated Zn-doped SnO2 nanorod cluster is one of the most promising nanomaterials for fabricating advanced low-temperature gas sensors. |
URI: | http://140.113.39.130/cdrfb3/record/nctu/#GT070051549 http://hdl.handle.net/11536/73484 |
显示于类别: | Thesis |