混合价态铁基金属有机骨架薄膜的制备与价态连续调控研究

Metal-organic frameworks (MOFs), as an emerging class of inorgaic-organic hybrid crystalline porous materials, have drawn broad interest in both fundamental and application research. MOF-based membranes have shown great promise in applications such as separation, sensing, and catalysis. To fine-tune the structure and functions of the MOF within a membrane is a critical technique sought after. The valence of metal in a MOF is one of the key parameters in determining many of its properties. To realize a continuous modulation of the valence state of the MOF while keeping its ordered skeleton in a MOF membrane is remarkably challenging in synthetic chemistry. To tackle the above problem, we propose to employ a solution-based electrochemical intercalation of ions to a series of Fe-based MOF membranes. This method can induce tunable mixed-valence states in MOFs and achieve a continuous valence modulation for the membranes. We will systemetically explore the impacts of the intercalation process on the composition, structure and morphology of the MOFs and the properties of the membranes, understanding the underlying mechanism of this electrochemical method. This study will provide useful guidelines for and insight on the continuous valence modulation for membrane-based materiels, opening up opportunities for the development of novel properties, applications and related fundamental science.

金属有机骨架（MOF）作为一类新型的无机有机杂化晶态多孔材料，在基础和应用领域有着广泛的研究兴趣，基于MOF的薄膜材料在分离、传感、催化等领域具有广阔的应用前景。在MOF成膜的基础上，如何对MOF薄膜实施精细化处理，以调控其中MOF的结构与功能，是MOF薄膜在应用中亟待发展的关键技术。MOF的金属价态对其很多性质都有重要影响，如何在薄膜状态下对MOF价态实现精细调控，而不破坏其骨架结构，在制备上还存在相当的困难。针对这一难题，本项目以铁基MOF薄膜为研究对象，利用液相电化学离子注入的方法，实现对薄膜中铁价态的连续调控，系统研究离子注入过程对MOF组成、结构、形貌以及薄膜性质的影响，并深入考察调控的微观机制。上述研究将为薄膜材料价态的精细连续调控提供思路和方法，为开发新的性质和应用，以及研究其中的基础科学问题提供更多可能性。

金属有机骨架（MOF）作为一类新型的无机有机杂化晶态多孔材料，在基础和应用领域有着广泛的研究兴趣，基于MOF的薄膜材料在分离、传感、催化等领域具有广阔的应用前景。本项目中，针对MOF及其薄膜材料在电化学体系中的行为和性质进行了研究，并针对性能调控尝试了各种改性手段。项目实施期间，合成了依托于碳布的MOF薄膜并对其进行热处理转化，成功应用于锂硫电池中电极和阻挡层，有效提高了电池的容量和循环性能。同时，还针对锂二氧化碳电池正极转化过电势高的困难，筛选出高效MOF催化剂，并系统研究了金属种类、孔道大小等结构因素对电池过电势、放电容量和循环性能的影响。在此基础上，设计制备了MOF衍生复合电极材料，进一步提升电池各项性能，并对材料设计各项参数进行了细致的对比研究，总结出优化电池性能的关键要素。