空心金属和金属氢氧化物纳米结构的制备和性能研究

发布时间：2019-02-26 17:29

【摘要】：环境污染、食品安全、能源危机等问题严重地威胁着人类的健康和可持续发展,成为人们迫切需要解决的问题。由于操作简便、检测速度快、准确率高、仪器便携等特点,表面增强拉曼光谱可以作为高灵敏度的检测手段在化学分子探测和识别方面有着广泛的应用前景。发展可控的生物相容性良好的、优良的表面拉曼光谱增强基底探针材料是有望获得到高灵敏度传感器的重要手段。氢能作为清洁经济的二次能源是不可再生化石能源的重要替代品。电解水制氢是其生产的重要方法,该过程的效率强烈依赖于催化剂的发展。因此开发高活性,低过电势的高效水电解催化剂是氢能大规模应用的前提条件。尤其是碱性溶液中使用的非贵金属催化剂,主要是希望得到高催化活性和高持久性,并且便宜的催化剂,因此3d过渡族金属氧化物/氢氧化物成为研究重点。本论文中以PS-NH2纳米球为模板,结合了化学电镀和去合金化等方法合成了NPAu。另一方面通过配位刻蚀沉积方法(CEP)合成了M(OH)2(M=Mn,Fe,Co,Ni)和钴系列二元Co M(M=Mn,Ni,Zn)复合氢氧化物。分别对以上两种材料进行了表面增强拉曼性能和电化学析氧性能的研究,得出以下结论:1.NPAu中空纳米结构,同时具有中空结构和连续多孔结构的特点,这种特点能显著提高拉曼增强效果,检测罗丹明R6G探针分子的极限浓度能达到~10-12M。研究表明,NPAu中空纳米结构的壳是互连互通的多孔结构,不仅大大增加了比表面积和吸附更多罗丹明R6G分子,而且纳米尺度的金韧带在激光激发下表现出强的电磁场,与邻近金韧带的磁场耦合作用制造了大量的热点(hot-spot),极大地提高表面增强拉曼效果。2.过渡族金属具有含量丰富,成本低的特点。M(OH)2(M=Mn,Fe,Co,Ni)和钴系列二元Co M(M=Mn,Ni,Zn)复合氢氧化物可作为便宜的电催化析氧反应催化剂,取代Ir,Ru等氧化物在碱性溶液中的应用。对于M(OH)2(M=Mn,Fe,Co,Ni),其中M2+(M=Mn,Fe,Co,Ni)与OH键结合的强度顺序是NiCoFeMn,所以电化学析氧活性的顺序为Ni(OH)2Co(OH)2Fe(OH)2Mn(OH)2;同时由于制备的结构是空心结构的特点,具有更多的比表面积和活性反应位点,比一般的相应物的电化学析氧性能也有一定的提高;对于Co M(M=Mn,Ni,Zn)复合氢氧化物,Co Mn和Co Ni复合氢氧化物的电化学析氧性能并没有有显著提高。Co Zn复合氢氧化物由于Zn对复合物结构的支撑和协同效应,同时空心结构的特点提供更多的电化学活性位点,Co Zn复合氢氧化物的电化学析氧性能显著增强。
[Abstract]:Environmental pollution, food safety, energy crisis and other problems seriously threaten human health and sustainable development, and become an urgent problem to be solved. Because of the advantages of simple operation, high detection speed, high accuracy and portable instrument, surface-enhanced Raman spectroscopy (SERS) can be used as a highly sensitive detection method in the detection and recognition of chemical molecules in a wide range of prospects. The development of controllable biocompatible and excellent surface Raman spectrum-enhanced substrate probe materials is an important means to obtain high sensitivity sensors. As the secondary energy of clean economy, hydrogen energy is an important substitute for non-renewable fossil energy. Hydrogen production from electrolytic water is an important method, and the efficiency of this process depends strongly on the development of catalysts. Therefore, the development of high activity, low overpotential water electrolysis catalyst is the prerequisite for large-scale application of hydrogen energy. In particular, the non-precious metal catalysts used in alkaline solutions mainly hope to obtain high catalytic activity and high persistence, and cheap catalysts, so 3D transition metal oxides / hydroxides have become the focus of research. In this paper, NPAu. was synthesized using PS-NH2 nanospheres as template, combined with chemical plating and de-alloying. On the other hand, M (OH) 2 (mn, Fe, Co, Ni) and Co series binary Co M (mn, Ni, Zn) complex hydroxides were synthesized by (CEP). The surface-enhanced Raman and electrochemical oxygen evolution properties of the above two materials were studied respectively. The conclusions are as follows: 1.NPAu hollow nanostructure has the characteristics of hollow structure and continuous porous structure at the same time. The maximum concentration of Rhodamine R6G probe molecule can reach ~ 10 ~ 10 ~ 12m 路m ~ (- 1), and the Raman enhancement effect can be greatly improved by this characteristic. The results show that the shell of NPAu hollow nanostructure is an interconnected porous structure, which not only greatly increases the specific surface area and adsorbs more Rhodamine R6G molecules, but also exhibits strong electromagnetic fields in nanoscale gold ligaments under laser excitation. The magnetic field coupling with the adjacent gold ligament creates a large number of hot spots (hot-spot), which greatly improves the surface-enhanced Raman effect. 2. M (OH) 2 (M (OH) 2, Fe, Co, Ni) and Co series binary Co M (mn, Ni, Zn) complex hydroxides can be used as cheap electrocatalytic catalysts for oxygen evolution reaction to replace Ir,. Application of Ru and other oxides in alkaline solution. For M (OH) 2 (mn, Fe, Co, Ni), the bond strength of M _ 2 (M _ x mn, Fe, Co, Ni) with OH is in the order of NiCoFeMn, so the order of electrochemical oxygen evolution activity is Ni (OH) 2Co (OH) 2Fe (OH) 2Mn (OH) _ 2; At the same time, because the prepared structure is hollow structure, it has more specific surface area and active reaction sites, and its electrochemical oxygen evolution performance is also improved. For Co M (mn, Ni, Zn) composite hydroxides, the electrochemical oxygen evolution performance of, Co Mn and Co Ni composite hydroxides has not been improved significantly. Co-Zn composite hydroxide is due to the support and synergetic effect of Zn on the structure of the composite. At the same time, the characteristics of hollow structure provide more electrochemical active sites, Co Zn complex hydroxide electrochemical oxygen evolution performance significantly enhanced.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ116.2;O643.36

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