金属-有机框架(MOFs)衍生材料及其在储能器件和电催化领域的应用

金属-有机框架(MOFs)是一类由金属离子/团簇和有机配体通过配位形成的具有多孔结构的无机-有机杂化材料。MOFs具有比表面积高、孔径均一、结构可调等优点,受到了人们的广泛关注。然而,MOFs的导电性和稳定性较差,制约了其应用的进一步拓展。以MOFs作为前驱体,通过水热反应或煅烧得到组成、形貌、结构可调的MOFs衍生材料,既能够保持MOFs材料结构多样性和多孔性的特点,又能有效提高其导电性和稳定性,近年来已成为该领域的研究热点。然而,MOFs衍生材料单一的组成和结构,使其能够提供的性能(如电容性能、催化性能)有限,极大地限制了其相关应用的发展。因此,近几年除了研究制备各种不同MOFs衍生材料外,研究者们主要从MOFs衍生材料的组成和结构方面出发,制备出多样化且在各方面应用中(如储能器件、催化)表现出优异性能的材料。MOFs衍生材料作为性能优异的应用型材料,其研究较为成熟的组成和结构分别主要包括多孔碳、金属氧化物、金属硫化物、金属磷化物、金属氢氧化物以及纤维状结构、中空结构、核壳结构等。MOFs衍生材料不仅具有高的比表面积、均一的孔径分布,通常还结合了衍生多孔碳的高导电性及其他衍生材料(金属化合物或掺杂的金属原子及杂原子,如N、P、S等)的优异性能(如电容性能、催化性能),从而发挥出更加优异的性能。其中,MOFs衍生金属化合物材料具备多孔结构,能够提供优异的容量性能及催化性能等,且其性能通常优于通过其他方法制备得到的同种材料。从结构方面出发,近几年,研究者们通过调控前驱体结构亦或是反应条件,制备得到多种不同结构的MOFs衍生材料。一方面,部分制备得到的结构(如核壳结构、中空结构)可以缓解MOFs衍生材料在使用过程中所受到的冲击,从而表现出优异的循环性能。另一方面,通过调控MOFs衍生材料的结构,使其活性位点得到充分的暴露,从而使其性能得到最大化的发挥。本文综述了MOFs衍生材料的研究进展,包括组成特点、结构调控,及其在储能器件、催化领域的应用,最后阐述了MOFs衍生材料研究领域当前面临的挑战以及未来的发展前景。

Metal-Organic Framework-derived Materials and Their Applications in Energy Storage Devices and Electrocatalysis

Metal-organic frameworks (MOFs), a kind of porous materials constructed from metal ion/cluster and organic li-gands, have been a major focus of materials science over the past decades. MOFs possess high specific surface area and uniform cavities, as well as structural tunability, which are promising for a variety of applications. However, the poor conductivity and low stability of MOFs restrict their further development of applications. In recent years, MOF-derived materials, obtained by hydrothermal and/or calcining process, which possess relatively higher conductivity and better stability while maintaining the structural advantages of MOFs, have become a research hotspot. However, the single composition and structure of MOF-derived materials, which can provide limited performance (such as capacitive properties, catalytic properties), greatly limit the development of its related applications. Therefore, in addition to research and preparation of a variety of different MOF-derived materials in recent years, researchers mainly foucs on the composition and structure of MOF-derived materials to prepare a variety of materials with excellent performance in various applications (such as energy storage and conversion, catalysis). As applied materials with excellent performance, composition and structure of MOF-derived materials have been studied maturely, mainly include porous carbon, metal oxides, metal phosphides, metal hydroxides, and fibrous structures, hollow structures, core-shell structures, etc. MOF-derived materials with large specific surface area, uniformly distributed cavities, always combine the porous carbon with high conductivity and other derived materials (metal compounds or doped metal atoms and heteroatoms such as N, P, S, etc.) with excellent performance (such as capacitance, catalytic properties), to play a rather excellent performance. Among them, MOF-derived metal compounds have porous structure, which can provide excellent capacity and catalytic properties, and the properties are usually superior to the same materials prepared by other methods. In terms of structure, in recent years, the resear-chers have prepared a variety of MOF-derived materials with different structures by controlling the precursor structure or the reaction conditions. On the one hand, partially prepared structures (such as the core shell structure and the hollow structure) of MOF-derived materials can alleviate the impact in the process of use, thus it can show excellent cycling performance. On the other hand, by regulating the structure of MOF-derived materials, the active sites are fully exposed, so that their performance can be maximized. In this review,we summarizes the recent progress of MOF-derived materials, including its composition, structural regulation, as well as their applications in energy storage, catalysis and other fields. Finally, the future direction and challenge of MOF-derived materials are discussed.