MOFs基纳米炭材料的结构设计及储能性能研究

Metal-organic frameworks (MOFs) are crystalline materials with periodic network structures that are self-assembled by the bonding of metal ions with polydentate organic ligands. The preparation of carbon nanostructures by carbonization of MOFs has become a hot topic, which plays an important role in application of MOFs and functional design of new carbon materials. However, up to now, there is a lack of knowledge regarding the interaction between ligands and metal as well as their variations inheritance relationship between MOFs and the carbonized products. The purpose of this project is to investigate the effects of carbonization conditions including temperature, soaking time, pressure, atmosphere and heating rate on the morphologies and structures of MOFs-derived carbon nanomaterials based on the understanding of carbon-metal interactions during the pyrolysis of MOFs, and finally to achieve the designable and controllable synthesis approach of new carbon nanostructures. Moreover, the MOFs-derived nanocomposites will be prepared by utilizing the induction of metal nanoparticles in carbon matrix. The electrochemical energy- storage performance of the MOFs-derived carbon nanomaterials and their composites will be investigated in detail. Our work is expected to not only broaden the application of MOFs as well as MOFs-derived carbon nanomaterials, but also provide a controllable and general strategy to prepare new carbon nanomaterials.

金属有机骨架（Metal-organic frameworks, MOFs）是有机配体与金属离子自组装形成的具有周期性网络有序结构的新材料，以其为原料通过热解制备纳米炭材料是目前研究的热点方向之一。针对MOFs成炭过程中配体和金属的相互作用鲜有研究、未能充分利用MOFs有序结构特征来可控制备炭材料的现状，本课题拟以阐明MOFs热解过程中碳-金属相互作用及其对成炭的影响为核心，考察炭化反应条件对MOFs成炭形貌、结构的影响及各组分在热解过程中的微观结构演变规律，揭示MOFs结构与热解产物的传承关系，最终通过调控工艺参数合成结构新颖且可控的MOFs纳米炭材料。利用碳对金属的诱导作用合成不同形貌结构的纳米金属/氧化物及其含炭复合材料，研究MOFs基纳米炭及其复合材料在储能方面的应用性能。以期拓宽MOFs的研究和应用范围，为设计合成新型纳米炭材料提供一条简单、可控、普适性强的新途径。

本课题针对MOFs在热解成炭过程中有机配体和金属的相互作用，充分利用MOFs有序结构特征及其成分的可选择性来可控制备炭材料。在系统深入研究MOFs热解的反应过程，并阐明了其反应机理的基础上，详细考察了各种工艺参数对产物的可控合成作用，为各类MOFs基炭材料及其复合材料的设计、合成与应用提供了详实的基础数据。取得了如下代表性成果：（1）从热力学和动力学的角度，系统地揭示了MOFs在热解反应中组成成分、微观结构和构型的演变规律，提出了较为完整的MOFs热解成炭机理模型，为MOFs炭材料的设计合成及应用提供了理论支持；（2）利用MOFs热解特性，通过调控其各阶段不同热解反应的发生，探究并归纳了多种不同类型MOFs基炭及其复合材料的合成策略，并进一步探索了各种工艺参数对MOFs材料与热解产物的传承关系的影响；（3）将合成所得的MOFs基炭材料应用于电化学储能器件，并以其中的典型材料，提出了多孔炭材料孔结构对锂离子存储性能的系统评价方式，建议了以N-6/N-Q的比值作为一个本征参数来考察N元素掺杂对电化学储钠性能的影响，为MOFs基炭材料作为储能材料并进一步开展实际应用研究奠定了基础。在Adv. Energy Mater., Small, Chem. Commun.,J. Mater. Chem. A, Chem. Eng. J.等杂志发表SCI论文24篇，获得国家发明专利授权3项，申报2项，培养博士生和硕士生9名。