少层六方氮化硼的制备及其复合金属纳米材料的应用

发布时间：2018-03-03 12:25

  本文选题：少层h-BN　切入点：球磨　出处：《江苏大学》2017年硕士论文　论文类型：学位论文

【摘要】：h-BN纳米材料作为近年来发现的新型二维纳米材料,具有很多优异的物理特性和化学性能,使其在治理环境水质污染方面、可再生能源工业化方面、新型微纳米电子器件方面都具有很大的应用前景。目前,高质量和可工业放大生产的层状h-BN的制备成为氮化硼商业化应用的限制因素。本文以商业化h-BN粉末为前驱体,采用次氯酸钠水溶液辅助球磨剥离方法开发出低成本、高产量的少层h-BN。这种方法可以获得少层(2-4层)h-BN,并且h-BN层状面内结构损坏小,产品的产率高达21%。以少层h-BN为载体,Ag纳米颗粒为催化剂,在NaBH4存在条件下有效地催化还原对硝基苯酚转化为对氨基苯酚,得到的一级反应速率常数为7.13×10-3s-1,大于商品h-BN负载Ag纳米粒子的一级反应速率常数,并且催化剂具有较好的稳定性,可以循环利用。实验结果表明,稳定的剥离过程可以为h-BN基层状材料的一系列重要应用开辟道路。进一步实验中利用新鲜制备的氯化四氨合铜,氯化六氨合钴和氯化六氨合镍等做为金属前驱体,与硼氢化钾混合球磨得到热分解前驱体,然后在900℃、氮气氛围下焙烧2h制备出少层六方氮化硼分别包裹纳米铜、钴、镍及钴镍合金(M@h-BN)的复合材料,实现了少层h-BN(约5?15层)的一步合成及具有规定尺寸的金属纳米粒子的同步还原。其中CoNi@h-BN表现出较好的催化氨硼烷析氢的活性与稳定性,实验测得的活化能Ea为28 kJmol-1,低于文献报道的大多数金属基催化剂的活化能(Ea)。性能的提高归因于封装后CoNi NPs的电子结构变化以及h-BN和氨硼烷的基本位点之间的强相互作用。此外,CoNi@h-BN表现的软磁性可以容易地循环利用,并保持高催化活性甚至再循环5次。Co@h-BN,Ni@h-BN,Cu@h-BN)复合材料表现出较强的热稳定性、磁性和较高的导热系数。尤其是Cu@h-BN的导热系数为253.7 Wm-1K-1,其热稳定性可以高达414℃,复合样品优异的性能为小巧或封装级的电子设备的热管理提出潜在解决方案。结合DSC-TG分析和物理化学表征结果,提出了M@h-BN的可能形成机理。同时,这种新型合成策略有望在电化学传感器,高导热粘合剂材料和燃料电池领域获得应用。
[Abstract]:As a new two-dimensional nanomaterials discovered in recent years, h-BN nanomaterials have many excellent physical and chemical properties, which make them in the treatment of environmental water pollution, renewable energy industrialization, At present, the preparation of layered h-BN with high quality and industrial amplification has become a limiting factor for the commercial application of boron nitride. In this paper, commercial h-BN powder is used as precursor. Low-cost and high-yield h-BNs were developed by using sodium hypochlorite aqueous solution assisted ball-milling stripping method. This method can obtain less layer 2-4 layers of h-BN, and the in-plane structure of h-BN layer is less damaged. The yield of the product was as high as 21. The reduction of p-nitrophenol to p-aminophenol was effectively catalyzed in the presence of NaBH4 on the basis of a few layers of h-BN as the carrier of Ag nanoparticles, and the reduction of p-nitrophenol to p-aminophenol was effective in the presence of H-BN. The obtained first-order reaction rate constant is 7.13 脳 10-3s-1, which is larger than the first-order reaction rate constant of commercial h-BN-loaded Ag nanoparticles, and the catalyst has good stability and can be recycled. The stable peeling process can open the way for a series of important applications of h-BN base-like materials. In further experiments, freshly prepared copper tetraamides, cobalt hexaaminochloride and nickel hexaaminochloride are used as metal precursors. The thermal decomposition precursor was prepared by mixing it with potassium borohydride, and then calcined at 900 鈩，

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