【作者】 郑辉；

【导师】 谷长栋；

【作者基本信息】 浙江大学 ， 材料科学与工程， 2015， 硕士

【摘要】 SnO是一类p型半导体材料,因其广泛的应用而得到大量的关注,特别是其可作为制备n型半导体SnO2的前躯体。本论文提出一种简单环保的离子热途径制备具有纳米结构的SnO粉体,对粉体的微观结构、形成机理以及退火获得SnO2的结构演变过程进行了详细表征,并分析了纳米结构氧化锡材料的微观结构与化学组成对气敏特性的影响规律。以氯化胆碱与尿素构成的深共熔溶剂(CU)作为反应介质和反应物,在其中溶解SnCl2,通过调节反应时间和水分含量,对SnO产物的微观形貌进行调控。在水量为1%的CU溶剂中,反应时间为1 min时制备出颗粒大小为4-6 m的SnO颗粒；反应时间为60 min时,得到大小为1-1.5um的绣球状SnO颗粒。当CU溶剂中的含水量为5%和15%时,SnO颗粒呈多层片状,并且随含水量增大,SnO颗粒构成的纳米片越少,比表面积更大。透射电子显微镜表明CU中水分含量的增加有助于SnO介晶的形成。对SnO介晶进行退火,得到由正交相和四方相混合构成的SnO2介晶结构,同时两相的成分比例取决于退火温度和反应溶液中的水分含量。对复合相SnO2进行气敏性能测试,发现正交相SnO2含量较多的复合相SnO2材料具有较高的乙醇气敏性能,并且对乙醇具有较高的选择性。在制备SnO粉体的反应体系中加入Co2+,获得了Co304/Sn02复合的空心纳米结构。研究发现当反应溶液中的Co2-的浓度为0.01 molL-1时,能制备出由正八面体和立方体混合的空心多面体结构Sn02。当Co2+的浓度为0.03molL-1和0.05molL-1时,仅有少量多面体结构生成。多面体结构SnO2材料表现出较高的乙醇气敏性能。更多还原

【Abstract】 SnO is a p-type semiconductor which has attracted vast attention because of its wide applications, especially as the precusor of the SnO2. In this dissertation, we successfully prepared nanostructured SnO crystals by using one facile and environmental-friendly method called ionothermal strategy. The micro-structure, formation mechanism and SnO2 formation after annealing of the SnO nanoparticles were characterized clearly. At the same time, the influences of the micro-structure and chemical compostion of the nano-structured tin oxides to the gas-sensoring performances were also analysized.The ChCl/urea (CU) based Deep Eutectic Solvent (DES) was used as the reaction medium and reagent, the SnO2 was dissloved in the DES. Through tuning the reaction time and water content of the CU solvent, the SnO with different size and morphology can be synthesized.4-6 nm SnO nanoparticle under 1 min reaction time and hydrangea-like SnO balls with size about 1-1.5 μm under 60 min reaction time can be synthesized in the CU solvents with 1% water content. While when the water content of the CU solvents were 5% and 15%, multilayer pancake-like SnO can be synthesized. The pancake-like SnO from CU solvent with 15% water content has less number of layers and larger specific surface area. Through the transmission electron microscope (TEM) analysis, we find that the water in the CU solvent can contribute to the formation of SnO mesocrystals.We can get SnO2 mesocrystals with orthorhombic and tetragonal phases when the SnO mesocrystals were under the annealing process. At the same time, the proportion of orthorhombic and tetragonal phases depends on the annealing temperature and the water content in the CU solvents. The gas sensor performance of the SnO2 with mixed phases was studied. We found that the SnO2 with larger amount of orthorhombic SnO2 has better ethanol gas sensor properties and seletivity towards ethanol.When the Co2+ was added to the reaction system, we can get nano-structure Co3O4/SnO2 composite. When the concentration of the Co2+ was about 0.01 molL-1, we can get hollow polyhedral SnO2 with octahedron and cube structure. While when the concentration of the Co2" was about 0.03 molL-1 and 0.05 molL-1, there was only a little amount of polyhedral SnO2. We found that the SnO2 samples with hollow polyhedral-structure have better ethanol gas sensor properties.更多还原