文档介绍：华中科技大学
硕士学位论文
SnO2/Au复合材料的制备及其气敏性研究
姓名:张丽芳
申请学位级别:硕士
专业:材料学
指导教师:刘向东
2011-01-15
华中科技大学硕士学位论文
摘要
目前,金属氧化物(MOX)气敏传感器在气敏传感器的研究和应用中占据主导地
位,为了改善其气敏特性,通常采用添加贵金属、制备纳米级材料等方式,但是当前
气敏传感器普遍存在工作温度偏高、对气体的选择性不够明显、对环境依赖性强等缺
点。如何改善传感器的气敏性能是传感器研究领域的关键与难点。
本文利用化学还原法制备出了纳米 Au 和 SnO2 纳米粒子,并研究了反应条件对纳
米 Au 形貌的影响。由透射电子显微镜(TEM)的结果可知,HAuCl4 与 K2C2O4 的摩尔
比是影响纳米 Au 形貌的决定性因素,随着摩尔比的减小,产物逐渐从纳米粒子转变为
网络结构的纳米 Au。
通过化学作用将 SnO2 纳米粒子吸附在纳米 Au 表面,合成了 SnO2/Au 复合材料,
探索溶液 pH 值对复合材料合成的影响。X 射线衍射(XRD)图谱证明,制备好的网状
纳米 Au 和 SnO2 纳米粒子按照一定摩尔比混合后,在强酸性条件下,形成了 SnO2/Au
纳米复合材料。
测试了复合材料传感器对乙醇(CH3CH2OH)和甲苯(C7H8)的灵敏度,研究了
气体浓度、工作温度对传感器敏感性的影响。实验发现,与纯 SnO2 传感器对比,复合
材料的敏感性有所提高,灵敏度随着气体浓度的升高而增大;此外,对 CH3CH2OH 最
佳响应温度从 350℃降到了 300℃。

关键词: 纳米金 SnO2 纳米粒子 SnO2/ Au 复合材料气敏传感器敏感性
I
华中科技大学硕士学位论文
Abstract
Metal Oxides (MOX) have being drawn more and more attentions as gas sensing
materials. Various strategies, such as doping, material nanosizing and incorporation of noble
metals particles into metal oxide gas sensing materials, have been adopted to improve their
sensitivity.
In this work, Au nanostructures and SnO2 nano-crystals have been prepared by
chemical method. The effect of preparation conditions on the morphology of Au
nanostructures have been investigated. The TEM results show that, the morphology of Au
nanostructures were decided by the molar ratio of the HAuCl4 and K2C2O4. With the
decreasing of the ratio, the morphology of products gradually evolutes to spider-web-like
architectures from nanoparticles.
SnO2/posite material has been synthesized through chemical interaction
between Au nanostructures and SnO2 nano-crystals. PH value is the decisive factor for its
synthesis. The XRD results indicates that, SnO2/pisite material can formate under
acidic conditions.
Gas-sensitive performances of the posite material have been investigated.
The dependence of gas-sensitivity on gas concentration and operating temperature has been
studied. Compared to Sn