熔盐电解法制备微观有序多孔碳和高熔点金属的研究

Porous carbon materials have been widely used in the research of the storage of hydrogen, lithium and energy and the support of catalyst owing to its unique physical chemical properties. Porous carbon materials include active carbon, templated carbon, carbon nanotube and carbide derived carbon etc. The structure and morphology of porous carbon are determined by its preparation process. In this proposal carbides of the metals of high melting point are used as raw materials by molten salt is electrolysis the metals in the carbide lose electrons, and move away from the carbides and deposit as metals on the cathode, and carbon remains and forms new porous carbon with uniform porosity, controllable pore size and structure order. By adjusting electrolysis parameters, the morphology and synthesis process of the metals and the porous carbon as well as the pore size of the porous carbon are controllable. The process makes full use of raw material and does not produce pollute substances. The study opens a new research area of porous carbon functional materials. The content of the proposal involves the process of metallurgical physical chemistry of the preparation of new microscopic order porous carbon materials and metals of high melting point by molten salt electrolysis method, and concerns the foundation of materials science of the characterization of the properties and morphology of metals and porous carbon, as well as relates to the area of electrochemical research and application of energy and lithum store. The aims of the work are to obtain the scientific rules of the preparations of the microscopic order porous carbon materials and their electrochemical properties as well as the metals of high melting point using carbides as anodes, and to develop metallurgical physical chemical method.

多孔碳材料具有优异的物理化学性能，被广泛应用于储氢、储锂、储能、催化载体等领域的研究中。多孔碳材料包括活性炭、模板碳、碳纳米管和碳化物衍生碳等，其结构和形貌与制备方法有关。本项目以高熔点金属的碳化物为原料，通过熔盐电解，使碳化物中的金属失去电子，脱离碳化物，在阴极上沉积为金属；留下的碳则形成孔隙均匀、孔径可控、结构有序的新型多孔碳材料，通过调控电解过程参数，控制多孔碳材料的孔结构和形貌及金属晶体的生长。整个过程充分利用原料，不产生污染环境的物质，开辟了新的多孔碳功能材料的研究领域。本项目研究内容涉及熔盐电解法制备微观有序多孔碳材料和高熔点金属的冶金物理化学过程、多孔碳材料与金属晶体的性质及形貌表征等材料科学基础、多孔碳材料储能、储锂等性质的研究与应用等领域。本项目旨在获得熔盐电解法制备新型微观有序多孔碳材料及其电化学性能，和以碳化物为阳极制备高熔点金属的科学规律，发展冶金物理化学研究方法。

本项目以碳化钛为原料，通过熔盐电解方法,成功地可控制备了高度疏松有序结构的碳化钛衍生炭（TiC-CDC）和金属钛与钛镍合金。研究了不同电解温度下熔盐电解制备的衍生炭的结构及作为超级电容器的储能性能，获得了电解温度和电压对衍生炭结构和储能性能的影响；研究了熔盐电解法制备高熔点金属及钛镍合金的动力学，获得了电解电流随着外加电压变化的规律，为熔盐电解制备高熔点金属提供了指导；研究了电沉积产物钛及钛镍合金的形貌和组成及电解质组成对钛镍合金的形貌和组成的影响规律，建立了一种短流程绿色环保的钛镍合金制备方法。.衍生炭呈现两种不同的生长方式，沿固体电极与熔盐的界面的横向生长和沿电极内部纵向生长。横向生长生成了一维炭棒，纵向生长生成了疏松的雪花状炭。衍生炭由有序的石墨和无序的碳两种结构组成，制备温度影响衍生炭的结构，温度升高，有序石墨的含量增加。在800 oC温度下制备的TiC-CDC晶体尺寸为4.4-4.7 nm，比表面积和孔体积分别达到904 m2/g和0.45 cm3/g。用碳化钛衍生炭组装的超级电容器呈现出优异的性能，以1 M Na2SO4溶液为电解质，3A/g电流密度下的电容值高达129F/g。.碳化钛作为阳极能够溶解进入NaCl-KCl熔盐中，溶解过程是金属钛失去两个电子的一步可逆反应。在1.3 V电压下电解制备的金属钛呈枝晶形貌，是晶格参数为=0.2956 nm、c=0.4684 nm的a相，纯度高、无杂质。以碳化钛为阳极、以NaCl-KCl-NiCl2熔盐为电解质，电解获得了钛镍合金。通过调控NaCl-KCl中NiCl2的浓度和电解电压，实现了对钛镍合金组成的调控。增加熔盐中NiCl2的浓度，钛镍合金中镍的含量增加。.与美国卡内基梅隆大学材料科学与工程系Rohrer教授、英国皇家学会Nanoscale的副主编、化学系教授金荣超开展了合作与交流；并多次参加国际会议并做分会主席在国际著名期刊《Journal of Materials Chemistry》等发表6篇Sci检索论文，培养硕士研究生7名。