SnO2纳米材料的制备及气敏性能研究-微电子学与固体电子学专业毕业论文5n02纳米材料的制备及气敏性能研究一般Sn02纳米材料及本文中的Sn02纳米空心球，主要原因是该材料暴露的{1l 1)晶面具有很高的催化活性，有助于氧化还原反应的快速进行。

采用水热法合成暴露{332}高指数晶面的Sn02正八面体，Sn02{332}JE／＼面体棱长为95nm，两顶点间距离为140nm，在最佳工作温度250。

C下，对800ppm 乙醇气体的灵敏度达2200，约为Sn02{111)最大灵敏度的12倍，且最佳工作温度低于Sn02{111)，响应恢复时间分别为1．5s和32s，气敏性能优于Sn02{111)八面体材料，原因是f332}晶面的催化活性高于{111)晶面，反应速率更快且最佳工作温度降低。

关键词：空心球；高指数晶面；气敏性能万方数据厦门大学硕士学位论文AbstractAbstractAs the science and technology of modem society develop rapidly,living standards improves，at the same time，environmental pollution is also becoming more and more serious，including gas pollution．Thus gas sensors are used to monitor the environment gas and sound the alarm in time，which Can effectively solve the gas pollution problem．In a variety of gas sensors，the gas sensor of metal oxide semiconductor has high sensitivity,low cost，long life and other advantages．Combining with the nanotechnology further improve the performance of gas sensitive．Sn02 nano material is one of the most common used gas sensitive substrate materials，but in practical application there are still some shortcomings，like poor selectivity and11igh working temperature．Thus for the sake of further improving the gas sensor applications of nano Sn02 materials，reducing size of materials，doping and some other methods are used．Among these methods，changing the microstructures Can effectively increase thethe exposed high specific surface area，then increase the amount of target gas．Regulatingenergy facets Can improve the surface reactivity of material，thus improve the reaction rate．In this study,two methods of changing the microstructures and regulating the exposed high energy facets to improve the performance of gas sensitive have been investigated．The connections between gas sensing a nd m icrostructure and crystal activity have also been explained．One step hydrothermal synthesis without any template has been used to preparediameter of which are 1 40-200 nln．The Sn02 hollowSn02 hollow nanospheres，thenanospheres are typically hierarchical structure，which consists of Sn02 nanoparticles．Compared with four kinds of organic gas as acetone，methanol，acetyleneand butane，the Sn02 hollow nanospheres shows excellentselectivity to ethanol gas．At the optimal operating temperature of250。

C，the sensitivity to 800ppm ethanol gas is 107，the response time is 1 2．3 S and the recovery time is 2 1．6 S．The reason for the better万方数据Sn02纳米材料的制备及气敏性能研究gas —sensing performance of Sn02 hollow nanospheres is its larger surface area andmore nano scale channels ．One step hydrothermal synthesis has been used to prepare Sn02 octahedralnanocrystals with exposed h i 曲一energy{1 1 1)facets ．The side lengthof t he octahedral Sn02{111)is between 150 and 250 nln ．Sn02{111)exhibited a maximum responseof 1 79 to 800ppm ethanol gas at the optimal operating temperature of 3 60。

C with aresponse time of 9．5 S and a recovery time of 6．7 S ．As a result of very hi曲catalyticactivity of the{1 1 1)crystal face ，Sn02{1 1 1)has better gas-sensing performance ．Hydrothermal synthesis has also been usedtoprepare Sn02 octahedralnanocrystals with exposed hi 曲一energy{332}facets ，which have well-definedoctahedral shapes ．The lengthis about 95 nln and the distance between two vertices is around 140 nln ．Octahedral Sn02{332}exhibited amaximum response of 2200 at250*C ，about 12 times to the response of Sn02{11 1)，with a response time of 1．5 S and a recoverytime of 32 S ．The catalytic activity of{332)facet is higher than{11 1) facet ，SO the gas-sensing performance of Sn02{3 32}isbetter than Sn02{1 1 1)．Key Words ：Hollow nanosphere ；Hi曲一energyfacets ；Gas sensitivity ．V万方数据厦门大学硕士学位论文目录目录Abstract．．．．．．．．．．．．．．．．．．．．．．．III 第1章绪论一1．1．1引言．1—1．2气敏传感器概述．2．1．2．1气敏传感器的发展概况．．2．1．2．2气敏传感器的分类．．3．1．2．3气敏传感器的发展方向．．5．1．3纳米材料的制备方法．8．1．3．1固相法．8．1．3．2液相法．．9．1．3．3气相法．10．1．4纳米Sn02材料介绍．11．1．4．1纳米Sn02的基本性质及应用．12．1．4．2纳米Sn02气敏材料的研究现状．12．1．5本文的选题意义和研究内容．．1 7．第2章实验方法和原理．1 8．2．1实验主要试剂和仪器．．1 8．2．2材料的表征分析方法．．1 9．2．3旁热式气敏元件的制作．．19．2．4气敏性能测试．．20．2．4．1测试电路．20．2．4．2气敏性能的主要指标．20．2．4．3气敏性能测试方法．22．V万方数据$n02纳米材料的制备及气敏性能研究2．4．4气敏机理分析．22．第3章分级结构Sn02纳米空心球的水热法制备及气敏性能．．25．3．1引言．．25．3．2 Sn02空心球的合成．．26．3．3 Sn02空心球的表征．．26．3．3．1形貌组成分析．27．3．3．2晶体结构分析．27．3．4 Sn02空心球的气敏性能测试及机理分析．．28．3．4．1不同目标气体的气敏性能．28．3．4．2不同工作温度下的气敏性能．29．3．4．3不同气体浓度下的气敏性能．30．3．4．4气敏机理分析．32．3．5本章小结．．34．第4章Sn02{111}1k面体的水热法制备及气敏性能．．35．4．1引言．．35．4．2 Sn02{111}的合成．一35．4．3 Sn02{111}的表征．．37．4．3．1形貌组成分析．37．4．3．2晶体结构分析．37．4．4 Sn02{111}的气敏性能测试．．38．4．4．1不同工作温度下的气敏性能．38—4．4．2不同气体浓度下的气敏性能．39．4．5本章小结．．41．第5章Sn02{332}l'Ffk面体的水热法制备及气敏性能．．43．5．1引言．．43．5．2 Sn02{332}的合成．43．5．3 Sn02{332}的表征．45．V1万方数据厦门大学硕士学位论文目录5．3．1形貌组成分析-45-5．3．2晶体结构分析．45．5．4 Sn02{332}的气敏性能测试．46—5．4．1不同工作温度下的气敏性能．46．5．4．2不同气体浓度下的气敏性能．47—5．5本章小结．．49．结论与展望．51-参考文献．．．53．攻读硕士学位期间的主要成果一64一致谢．65．万方数据Sn02纳米材料的制备及气敏性能研究ContentAbstract ．．．．．．．．．．．．．．．．．．．．．．．．．I Chapter 1 Introduction -1-1．1 Foreword．．．．．．．．．．．．．．．．．．．．-1-1．2 Overview of Gas Sensors 一2—1．2．1 Status ofGas Sensors ．．．2．1．2．2 Types of Gas Sensors ．．-3-1．2．3 Development Trend ofGas Sensors ．-5-1．3 Preparation of Nanomaterials ．．-8-1．3．1 Solid State Method ．8．1．3．2 Liquid Phase Method ．．-9-1．3．3 Vapor Phase Method ．一10—1．4 Introduction of Sn02 Nanomaterials ．-1 1-1．4．1 Basic Properties and Applications of Sn02 Nanomaterials ．．-12- 1．4．2 Statusof Sn02 Gas-sensing Materials ．-12-1．5 Significance and Research Contents ．．-17一Chapter 2 Experimental Method andPrinciple ．．一1 8-2．1 Main Reagent and Instrument 一1 8-2．2 Characterization and Analysis -19-2．3 Fabrication of Gas Sensors ．．．1 9．2．4 Tests of Gas-sensing Properties ．．一20—2．4．1’I’est Circuit ．．20．2．4．2 Major Indexes of Gas—sensing Properties ．．一20一2．4．3 Test Methods of Gas-sensing Properties ．一22-2．4．4 Analysis of Gas-sensing Mechanism -22- Chapter 3 Synthesis and Gas—sensing Performance of Hollow Sn02V|Il万方数据厦门大学硕士学位论文ContentNanospheres ．．．25．3．1 Foreword ．．．25．3．2 Synthesis of Hollow Sn02 Nanospheres -26- 3．3 Characterization of Hollow Sn02 Nanospheres ．．-26-3．3．1 MorphologyAnalysis -27-3．3．2 Crystal Stm舭Analysis ．．-27-3．4 Gas-sensing Tests and Mechanism Analysis ．．-28-3．4．1 Gas-sensing Properties in Different Target Gas ．．-28—3．4．2Gas-sensing Properties under Different Temperatures -29—3．4．33．4．4 Analysis Gas—sensing Properties in Different Concentration ofGas -30-ofGas—sensing Mechanism ·32·3．5 Summary ．．-34-Chapter 4 Synthesis and Gas—sensing Performance of Sn02{lll}．35-4．1 Foreword．．．．．．．．．．．．．．．．．．．．．．．．35．4．2 Synthesis of Sn02{lll} ．-35-4．3 Characterization of Sn02{lll} ．．一37-4．3．1 MorphologyAnalysis -37-4．3．2 Crystal Structure Analysis ．．-37-4．4 Gas—sensing Tests of Sn02{lll} ．．-38- 4．4．1 Gas-sensing Properties under Different Temperatures -38-4．4．2 Gas-sensing Properties in Different Concentration of Gas 一39-4．5 Summary ．．-41-Chapter 5 Synthesis and Gas-sensing Performance o f SN02{332}．一43—5．1 Foreword．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．43．．5．2 Synthesis of SN02{332} -43-5．3 Characterization of SN02{332} ．．-45-5．3．1 MorphologyAnalysis -45-5．3．2 Crystal S缸uctl】re Analysis ．．一45一I×万方数据Sn02纳米材料的制备及气敏性能研究5．4 Gas-sensing Tests of SN02{332} ．-46—5．4．1 Gas-sensing Properties under Different Temperatures 一46-5．4．2Gas-sensing Properties in Different Concentration of Gas 一47—5．5 Summary ．．一49-Summary and Prospect ．一5 1一I己eference ．．53．Achievments ．．64．Acknowledge -65-X万方数据厦门大学硕士学位论文第1章绪论第1章绪论1．1引言在瞬息万变的现今社会，人们物质文化水平随科学技术发展日益提高的同时，环境受到的污染也越来越严重，包括水质污染、大气污染等。