多功能纳米材料的制备与表征

【作者】 张艳舞；

【导师】 李志华；

【作者基本信息】 山东师范大学 ， 物理化学， 2009， 硕士

【摘要】 低维纳米材料因其具有独特的物理化学特性以及在各个不同领域的广泛应用而受到国内外许多科研小组的广泛关注。钒氧化物纳米材料因为具有良好的催化性能、传感特性及电子传导特性而成为研究低维纳米材料物理化学现象的理想体系。尤其是对钒氧化合物纳米线、纳米带、纳米管的结构与性能的研究日益深入。另外,稀土正硼酸盐纳米材料因其独特的发光性能、电磁性能引起了广大科研小组的浓厚兴趣,是低维纳米材料领域研究的一个热点内容。本文在综述了大量有关无机纳米材料制备与表征的基础上,发展了水热合成纳米材料的软化学合成方法,并利用软化学的合成路线、温和的反应条件和可控的反应步骤设计了整个实验进行的全部过程。实现了对一系列钒氧化合物纳米材料(钒氧纳米线、钒氧纳米带、钒氧纳米管)、稀土正硼酸盐纳米材料(硼酸盐纳米管、硼酸盐纳米管束)的有效合成,并对所合成的纳米结构用XRD、SEM、TEM、HRTEM、IR、BET和DTA-TG等表征手段进行了分析。具体的研究过程如下:1.采用水热法在同一体系内成功合成了钒氧化物的纳米线、纳米带。研究分析了反应的各个影响因素如反应时间、反应温度、表面活性剂的用量和溶液的pH值等,实现反应的控制合成。同时对反应的机理进行了解释。2.研究发现,钒氧化物纳米管的制备中,胺类物质在纳米管形成过程中起着重要作用。本文以十八胺作为软模板,用乳化剂OP-10优化反应条件,成功合成了多层钒氧化物纳米管状材料,同时探究了反应温度、反应时间等因素对多层钒氧化物纳米管的影响。以XRD、SEM、TEM、HRTEM等对产物结构和形貌进行了表征。3.在180°C下直接将水合V2O5纳米线转变成VO2·nH2O的磁性纳米管。测试了钒氧化物纳米管的磁滞回线,研究了其磁学性能。并用XRD、TEM对VO2·nH2O的磁性纳米管的结构和形貌进行了表征。4.在180°C条件下通过水热合成法制备了微米级钒氧化物六边形钒氧化合物晶体的合成。并用TEM对其晶体形貌进行了表征。5.首次通过水热法合成了稀土正硼酸盐纳米管和纳米管束,研究了YBO3:Eu纳米管状化合物的形成机制。据文献报道,YBO3晶体是一种具有vaterite构型的化合物,这种化合物在溶液中比较容易形成片状。在我们的实验体系里,YBO3:Eu纳米管和纳米管束通过表面活性剂辅助水热法被成功控制合成。并用XRD、TEM、HRTEM、IR、BET和DTA-TG等表征手段对所合成的纳米管状结构进行了详尽的表征。希望能对今后进一步深入探索其纳米管状结构的物理化学性质及其应用研究起到一定的借鉴作用。更多还原

【Abstract】 Low-dimensional nanostructures, have attracted a great deal of attention for their unique physical and chemical properties and more extensive potential applications in various fields. Among them, vanadium oxides with different nanostructure were considered as one of the most important nanomaterials due to theirs applications in catalysts、chemical sensors and electrical transportation. They were regarded as an ideal system on the research of physical and chemical phenomenon in low-dimensional field. The research on the structure and property of vanadium oxide nanotubes、nanowires、and nanobelts were more and more thoroughly. There were also important topic in current research filed for many researchers to synthesize rare-earth borate compounds with nanostructure due to theirs luminescence and catalytic properties.A facile chemical method which had been reported were futher to developled based on analyzing the synthesized method and characterization technique. Vanadium oxide nanomaterials and rare-earth borate nanotubes were fabricated by controllable synthesized method under suitable hydrothermal method at low temperature. These nanostructure were characterized by XRD、SEM、TEM、HRTEM、IR specta、BET and TG-DTA. The main contens were as following.Hydrothermal method has been employed to fabricated the nanowires and nanobelts of vanadium oxides in NH4VO3 solution by adjusting and controlling the reaction conditions with the assistance of surfactants. The reaction factors and reaction process were further studied.Consulted the previously investigation, we noticed that amine played an important role in the procedure of NTs-VOx·nH2O fabrication by hydrothermal method. Therefor, we added octadecylamine into NH4VO3- -Emulsifier OP-10 -water systems and finally multilayer vanadium oxides nanotubles were obtained. These structures of nanotubes were detailly characterized by HRTEM. At the same time, reaction factors、the reaction mechanism and structure of products were elucidated.we made a simple systhesis method that V2O5·nH2O nanowires were translated magnetic VO2·nH2O nanotubes under 180°C for 8h. The hysteresis graph was analysised.In addition, we made a try to fabricated hexagonal vanadium microncrystals. These vanadium microcrystals were characterized by TEM.The rare-earth borate compound nanotubes and bunchy nanotubes were successfully systhesized by hydrothermal method for the first time. We discussed the formation mechanism of nanotubes and bunchy nanotubes. YBO3 was one of the compound with vaterite structure, it has a tendency to growth flake in solution. The of nanotubes and bunchy nanotubes were obtained by controllable synthesized method under hydrothermal method with the assistance of surfactants. The as-prepared nanotubes and bunchy nanotubes were characterized by XRD, TEM、HRTEM、IR、BET and TG-DTA. It may provide an opportunity for studying physical or chemical properties and potential applications of and nanotubes bunchy nanotubes in future.更多还原