【作者】 张萌；

【导师】 张密林；

【作者基本信息】 哈尔滨工程大学 ， 材料学， 2008， 博士

【摘要】 离子液体具有独特的结构和物理化学性质,近年来在无机纳米材料制备方面得到广泛的重视,尤其在纳米材料的微结构控制方面占有重要的地位,发挥了传统溶剂所不具备的优点,成为纳米材料制备领域中的研究热点之一。本论文以离子液体为介质,实现了CuO晶体在离子液体中的可控生长,合成了不同形貌的纳米材料,探讨了可控生长的机理,并剖析了纳米材料形貌与性能间的关系。通过离子液体的热分解,不但首次合成了配合物[Cu（N-MeIm）₄（BF₄）₂]（N-MeIm=N-甲基咪唑）,而且在不加入任何还原剂的条件下成功制备出Cu₂O、Cu和Ag,提出了可能的形成机理。采用一步法和两步法分别合成了离子液体[BMIM]Cl（1-丁基-3-甲基咪哗氯化物）、[BMIM]BF₄（1-丁基-3-甲基咪唑四氟硼酸盐）和[BMIM]PF₆（1-丁基-3-甲基咪唑六氟磷酸盐）,借助红外光谱分析和热重分析表征了其化学结构和热稳定性。以离子液体[BMIM]BF₄为反应溶剂,采用溶剂热法在200℃反应20h,合成了空间群为P2_1/n的单斜晶系配合物[Cu（N-MeIm）₄（BF₄）₂];通过改变反应物浓度、反应温度和反应时间,进一步加强离子液体[BMIM]Cl和[BMIM]BF₄的热分解程度,使其发生碳化,以碳为还原剂将Cu（Ⅱ）和Ag（Ⅰ）还原,进而制备出氧化亚铜、单质铜和纳米银。采用微波-离子液体法在8min内实现了不同形貌CuO的可控合成。考察了铜源、离子液体种类、NaOH浓度、离子液体含量、微波加热功率以及反应时间等参数对纳米CuO形貌的影响。以硝酸铜为铜源,在[BMIM]BF₄中合成了由宽度约0.8μ,m、长度约4.5μm的纳米片交叉排列的十字状花形CuO,在[BMIM]Cl中合成直径约40nm的CuO纳米棒,在水溶液中合成了纳米片同向排列的蛹状CuO;以醋酸铜为铜源,在[BMIM]BF₄中合成了柳叶状CuO纳米片,延长反应时间合成了柳叶状纳米片聚集而成的菊花状CuO,增加离子液体含量合成了柳叶状纳米片分裂而成的CuO纳米棒。采用溶剂热-离子液体法在100～140℃实现了不同形貌CuO的可控合成。考察了铜源、反应物浓度、反应温度、反应时间、离子液体种类、表面活性剂及反应物加入顺序等参数对CuO形貌的影响。以醋酸铜为铜源,在[BMIM]Cl中140℃反应20h合成了长度70～100nm,直径15～20nm,两端为半球型CuO纳米棒。以氯化铜或硝酸铜为铜源,在[BMIM]BF₄和[BMIM]Cl中,合成了单斜相结构的CuO纳米片,添加表面活性剂聚乙二醇后,形成表面光滑的CuO微球。以硝酸铜为铜源,先后加入[BMIM]BF₄和NaOH溶液,合成了由厚度65～80nm、长度4～5μm、宽度约500nm、末端成60°尖角的纳米片在中间紧扎而形成的新型束状CuO。考察了不同形貌CuO对催化、电化学和光学性能的影响。研究表明,纳米CuO的尺度、比表面积、表面状态以及排列方式都将对高氯酸铵热分解反应和异丙苯氧化反应产生影响;柳叶状纳米CuO电极材料在Li/CuO半电池中具有良好的电化学性能;与体材料比较,CuO纳米棒、纳米片的光学禁带宽度均发生了不同程度的蓝移。更多还原

【Abstract】 Ionic liquids with unique structure and outstanding physical and chemistry properties were widely used in the fabrication of inorganic nanomaterials, especially in the field of the control on microstructure. Ionic liquids with great advantage over the traditional solvents have been attractive for its abroad applications in the controlled synthesis of the inorganic nanomaterials.In this work, CuO crystals with various morphologies were controlled synthesized in ionic liquids system. The mechanisms for formations of controlled growth and the relationship between morphology and property were investigated. By the decomposition of ionic liquid, the novel complex [Cu（N-MeIm）₄（BF₄）₂] has been synthesized, and Cu₂O, Cu and Ag have been prepared. The possible mechanisms for formations were proposed.Ionic liquids of [BMIM]Cl.[BMIM]BF₄ and [BMIM]PF₆ were prepared through Direct Method and Two-step Method, respectively. The chemical structure and thermal stability of the final products were characterized by Infrared spectra and Thermogravimetry. The novel complex [Cu（N-MeIm）₄（BF₄）₂] has been synthesized successfully,which belonged to monoclinic with space group P2₁/n, by solvothermal method at 200℃for 20h in [BMIM]BF₄.The effect of reaction conditions such as the reagent concentration, reaction temperature and reaction time was discussed. [BMIM]Cl and [BMIM]BF₄ were carbonized to form carbon by enhancing the decomposition degree. The carbon was the reducing agent that converted Cu（Ⅱ） and Ag（Ⅰ） to Cu₂O, Cu and Ag.We adopted microwave-assisted ionic liquids method to controlled synthesize CuO nanomaterials with different morphology in 8min. The effect of reaction conditions such as copper sources, ionic liquids species, NaOH concentration, ionic liquids content, microwave power and reaction time were discussed. With copper nitrate as copper source, flower-like CuO has been synthesized in [BMIM]BF₄, which cross arranged with willow nanoplatelet of about 0.8@μm in width and 4.5μm in length;CuO nanorods have been synthesized in [BMIM]Cl;chrysalides-like CuO has been synthesized in H₂O,which arranged with nanoplatelet at the same direction. With copper acetate as copper source, we have prepared willow-like CuO nanoplatelet in [BMIM]BF₄,chrysanthemum-like CuO consisted of nanoplatelet by prolonging reaction time and CuO nanorods split from nanoplatelet by increasing ionic liquids content.We adopted solvothermal-assisted ionic liquids method to controlled synthesize CuO nanomaterials with different morphology at 100-140℃. The effect of reaction conditions such as copper sources, reagent concentration, reaction time, ionic liquids species, surfactants and the order of adding reagent was discussed. With copper acetate as copper source, CuO nanorods with 70-100nm in length and 15-20nm in diameter have been synthesized in [BMIM]Cl at 140℃for 20h. With copper nitrate or copper chloride as copper source, monoclinic CuO nanoplatelet or microspheres have been synthesized in [BMIM]Cl or [BMIM]BF₄.With copper nitrate as copper source and the adding of [BMIM]BF₄ before NaOH, we synthesized sheaf-like CuO consisting of nanoplatelets with lengths of 4-5μm, thickness of 65⁸0nm and end angle of 60°.Moreover, we study the relationship between property and the morphology of CuO nanomaterials. The effect of CuO morphology such as nano-scale, specific surface area, surface state and arrangement style on catalysis of ammonium perchlorate decomposition and the oxidation of cumene to cumene hydroperoxide was discussed. The willow-like CuO nanoplatelet had good electrochemical property as the electrochemical materials of Li/CuO cell. There were blue shifts of band gap energy for CuO nanorods and nanoplatelet.更多还原