【作者】 周俊；

【导师】 杨晴；

【作者基本信息】 中国科学技术大学 ， 无机化学， 2013， 博士

【摘要】 本文旨在设计和发展贵金属单分散纳米晶和硒碲硫属化合物低维功能纳米材料的液相合成方法。在文献总结和前期研究工作基础上,通过设计新体系液相合成路线并成功制备出油水双溶性贵金属单分散纳米晶、自组装CdTe纳米线以及超薄的单个五原子层Bi2Se3纳米片等多种低维纳米结构,并研究和探讨了其纳米催化、电子输运等性质。主要研究内容及研究结果归纳如下：1.设计和发展了一种温和的贵金属单分散纳米晶的液相合成方法。具体选择在乙二醇体系中,利用油胺做为配位与包裹试剂,成功地制备出既能溶于水相又能溶于油相的贵金属单分散纳米晶,其中包括Au、Ag、Pd、Pt以及其双金属单分散纳米晶。同时,通过改变溶剂与配位试剂比例、反应温度等条件获得了不同尺寸的贵金属单分散纳米晶。并且通过对反应过程的研究,阐明了所设计的合成反应路线的反应机理以及所制备贵金属单分散纳米晶的油、水双溶性的形成原因,并在水相和油相中利用所合成的贵金属量子点作为催化剂进行了suzuki和脱卤反应研究。结果显示,所合成的油水双溶性贵金属单分散纳米晶能很好的适用于油相和水相催化,并且产率都在95%以上。2.利用贵金属在催化硝基氢化反应中的催化速率快、条件温和、体系简单等特点,以上述所制备的贵金属单分散纳米晶为催化剂,设计了以叔丁胺氢化硼(C4H9NH2BH3)代替传统的硼氢酸盐作为氢源,环己烷作溶剂的非水相新型贵金属纳米催化硝基氢化体系。新体系成功避免了传统水相硼氢酸盐氢化体系选择性差的不足,成功实现了含有多官能团化合物中选择性的高效硝基氢化反应,反应的选择性和转化率均超过99%。3.设计和发展了一种新颖的多级自组装CdTe纳米线的制备方法,利用CdCl2和二苯基二碲做前?源,在油胺体系中通过加入三(2-乙基己基)磷酸作为表面活性剂,通过自组装过程实现了包括纳米线在内的CdTe多种形貌的合成。所合成的纳米线最长达20μm,并且对于可见光有着良好的光电响应性质,能够很好的用于纳米器件的构造中。4.在前期工作的新型乌尔曼反应的基础上,设计和发展了一种更加迅速的通过金属和非金属双自由基化合来制备低维纳米材料的方法.反应中具体利用三苯基铋和二苄基二硒,在油胺油酸体系中成功合成出单层结构的Bi2Se3超薄纳米片,并通过各种表征证实Bi2Se3单层超薄性。更多还原

【Abstract】 This dissertation is intended to develop the synthesis of noble metal monodisperse nanocrystals and chalcogenide compounds in functional nanomaterials respect. On the basis of the preliminary work, we summarized the insufficient contents of noble metal monodisperse nanocrystals and chalcogenide compounds in synthesis and application, and succeeded in preparation of noble metal monodisperse nanocrystals with both water-and oil-solubility, self-assembly CdTe nanowires and ultrathin monolayer Bi2Se3nanoflakes. The relevant properties characterizations were also performed. The details are summarized briefly as follows:1. A facile approach for the preparation of highly uniform and controllable noble metal nanoparticles, including Au, Ag, Pd, Pt, and their bimetals with different sizes in ethylene glycol at relative low temperature using oleylamine as a stabilizer was reported. The synthesized noble metal nanoparticles can be well dispersed in both water-and oil-based phases, and they are suitable for catalysis in both systems without any additional surface modifications. The detail mechanism of reaction and solubility of the nanoparticles was also elucidated.2. A new catalysis system was developed for the reductions of nitroaryl compounds using borane-tert-butylamine (BTB) as the hydrogen source instead of NaBH4. The new system of cyclohexane media different from the traditional NaBH4aqueous system can hydrogenate nitroaryl without influence of other reductive perssads, like carbonyl. Meanwhile, the new system performed an extremely high selectivity and conversion which were both up to99%.3. A novel multi-step self-assembly of CdTe nanowires and other morphologies of CdTe nanoparticles was designed and developed in oleylamine system with using CdCl2and diphenyl ditclluride as the precursor and adding tris(2-ethylhcxyl) phosphate as the surfactant. The as-synthesicd nanowires up to a maximum of20μ m, has good photoelectric properties for the visible light response, which can be very good for the fabrication of nanodevices 4. Based on the new Ullman reaction of the preparatory work, by further improving the reaction source, we synthesized ultrathin Bi2Se3nanoflakes of monolayer structure in oleylamine and oleic acid system with triphenyl bismuth and dibenzyl diselenide, and proved the monolayer structure of Bi2Se3by various characterizations.更多还原