【作者】 杜德娟；

【导师】 曹敏花；

【作者基本信息】 东北师范大学 ， 无机化学， 2008， 硕士

【摘要】 纳米材料由于其卓越的光学、电学、磁学和催化等性能而受到了人们广泛的关注,它的应用领域遍及材料学的各个领域,目前已成为材料领域中最活跃和重要的一部分。研究发现纳米材料的尺寸、形貌对纳米材料的性能有着很大的影响,所以纳米材料的形貌及尺寸可控合成是一项很重要也很有实际意义的工作。通过合成来探究纳米材料的形态形成机理与生长动力学,进而揭示纳米材料的微观结构、尺寸大小和生长形貌的规律,对进一步指导我们的实验研究是非常关键的。纳米材料的合成方法有很多,其中溶液法反应过程较简单、温和,得到的产物纯度高、分散性好,便于实现工业化和产业化。因此本文中采用溶液法合成了几种重要的纳/微米材料并对其性质进行了初步的研究。主要的内容如下:普鲁士蓝微米材料的合成及性能研究利用超声辅助的常温溶液法合成了不同形貌的M3[Co(CN)6]2(M=Zn, Co, Ni, Mn)微米材料,主要对Zn3[Co(CN)6]2进行了细致的探讨。我们合成了尺寸均匀的Zn3[Co(CN)6]2微米球和多面体,通过TEM,SEM研究了Zn3[Co(CN)6]2的形貌,并且讨论了浓度等参数对产物形貌的影响。其中多面体在铜网上有明显的自组装现象。进一步的研究发现球和多面体都是由小的纳米粒子聚集而成的。此外,N2的吸附-脱附性能测定证实Zn3[Co(CN)6]2微米球和多面体都是微孔结构,微米球和多面体的BET表面积分别为428.20、441.36 m2g-1,总的孔体积分别为0.2157、0.2395 cm3g-1。α-Fe2O3空心纳米球的合成及性能研究通过络合剂辅助的水热法合成了空心和实心的纳米球,分别用XRD,TEM,SEM表征了其成分和形貌,从透射和扫描电镜可以清晰的看到空心和实心的纳米球都是由更小的纳米粒子组成的,并且通过一系列的实验讨论了各种实验参数对产物形貌的影响,进而探讨出了空心球的形成机理;此外,我们测试了空心球的磁性和气体吸附性能。5K和300K的磁滞回线说明α-Fe2O3空心纳米球在温度低时表现为反铁磁性,而温度高时为弱铁磁性,这与体相材料是相同的,但空心纳米球的转变温度为181K,远远低于体相的263K。ZFC和FC曲线在整个温度范围内是分裂的,与体相(整个范围内是重合的)不同。N2吸附测试证实空心的α-Fe2O3为微孔结构, BET表面积为30.68 m2/g,较亚微米粒子大很多。不同形貌微米硫化铅的合成及性能研究通过表面活性剂(PVP)辅助的水热法合成了硫化铅的星形和类一维微米材料,分别用XRD,TEM,SEM表征了其成分和形貌。通过一系列的实验研究了各个实验条件对产物形貌的影响;此外,我们初步研究了不同形貌的硫化铅微米结构的紫外-可见光谱。更多还原

【Abstract】 Nanomaterials has been paid universal attentions for their prominent optical, electrical, magnetic and catalyze properties. Its application relates to every domain of material and has become one of its most important and attractive part. It is reported that the size and morphology of nanomaterial have obvious influences on properties, so the controllable synthesis is very important and significant. During which the exploration of microstructure, formation mechanism and growth kinetic all are key to the future experiments.Various methods have been developed for synthesizing nanomaterials, among of which the solution synthesis has many merits, For example, the reacting condition is relatively simple and mild, and the obtained product is much more pure and monodisperse. So we adopted solution synthesis herein and have obtained several important nano-functional materials, in addition we studied their elementary applied properties. The primary content of this paper is as following.Synthesis and characterization of Prussian blue microstructures morphology controllable M3[Co(CN)6]2(M=Zn, Co, Ni) microstructures were synthesized in solution under ultrasonic condition. herein we mainly studied Zn3[Co(CN)6]2. Uniform Zn3[Co(CN)6]2 microspheres and polyhedrons were synthesized, and TEM, SEM were carried out to characterize the morphologies. Experimental parameter influences were also carried out in detail. What’s interested us here is that self-assembly were observed obviously when the microparticles dispersed in alcohol were dropped on a copper grid or a glass substrate without any further treatment. Further investigation suggested that both spheres and polyhedrons are aggregated by small nanoparticles. N2 adsorption measurements verified the existence of micro-pores in both Zn3[Co(CN)6]2 microspheres and micropolyhedrons. The BET surface area of spheres and polyhedrons are 428.20, 441.36 m2g-1 respectively. The total pore volume are 0.2157, 0.2395 cm3g-1 respectively.Synthesis and characterization ofα-Fe2O3 urchin-like hollow nanostructures hollow and solid urchins were obtained in hydrothermal condition under the assistance of ligand. XRD, TEM, SEM were carried out to characterize the composition and morphology of the urchins. It is obviously seen that both hollow and solid urchins are composed of small nanoflakes. Series of experiments were also carried out to discuss the influences of experimental parameters. the two-step formation mechanism was speculated firstly and then verified by experiments. Magnetic and N2 adsorption properties were also carried out. The hysteresis loops at 5K and 300K clearly confirm the fact that hematite behaves antiferromagnetic at low temperature and weak ferromagnetism above morin transition temperature (TM). zero-field-cooled (ZFC) and field-cooled (FC) curves split during the whole temperature region. Normally, bulk hematite has a Morin transition from the low-temperature antiferromagnetic phase to a weakly ferromagnetic phase at 263 K. But here it should be noted that the TM value in differential ZFC curve (inset in Figure 5c) is found to be 181 K, which is much lower than the bulk transition temperature. N2 adsorption measurements illuminated the micro-pore structure ofα-Fe2O3 hollow urchins. The BET surface are is 30.68m2g-1, which is much larger than that of the submicron particles.Synthesis and characterization of PbS microstructures star-shaped dendrites and strips were synthesized in hydrothermal system at the assistance of surfactant(PVP), XRD, TEM, SEM were carried out to characterize the composition and morphologies. In addition, we studied the IR-VIS spectrum of both dendrites and strips.更多还原