基于金属-有机骨架前驱体的先进功能材料

由于金属-有机骨架(metal-organic frameworks,MOFs)结构中含有碳源(有机配体)和金属源(金属或金属簇)物质,以MOFs为前驱体合成先进功能材料,如纳米多孔碳材料和金属氧化物纳米材料,是目前MOFs化学以及新功能材料研究领域一个新的热点。本文综述了近年来以MOFs为前驱体制备碳材料(纳米多孔碳材料、碳纳米点、碳纳米管等)、金属氧化物纳米材料(单金属氧化物Fe2O3、Zn O、Co3O4、Mg O、In2O3等;多金属氧化物纳米复合材料Gd2O3/Eu2O3、Fe2O3@Ti O2等)、金属氧化物/碳纳米复合材料(Fe3O4/C、Zn O/C等)等的合成方法,以及这些先进功能材料在超级电容器(supercapacitor)、氧还原反应(ORR)催化剂、氢气吸附、CO2捕获、光催化制氢催化剂等研究领域的应用,并对其今后的发展进行了展望。     

金属有机骨架材料在催化中的应用

金属有机骨架(MOFs)材料是一种相对新型的多孔材料,由于其结构的多样性、可设计性、可剪裁性以及超高的比表面积,近年来吸引了广泛的研究兴趣,并在很多领域展现了潜在的应用前景.特别是在催化方面的应用更受到了强烈的关注.本文的前两部分主要以催化活性位点的来源进行分类,包括配位不饱和金属中心、功能性有机配体、化学修饰接入功能位点以及嵌入在MOFs孔内的金属配合物或金属纳米颗粒等,总结了近几年来MOFs及其复合材料在多相催化方向取得的一些进展.同时在后面两部分也简要地介绍了MOFs在光催化及以MOFs为模板构筑的多孔纳米材料在催化(特别是电催化)方面的一些应用.最后,对MOFs在催化方面的应用前景做了展望.     

以MOFs为前驱体的多孔金属氧化物催化剂研究进展

多孔金属氧化物具有高比表面积、大孔径、特殊的形貌和结构特性,广泛应用于催化、锂离子电池、太阳能电池、气敏传感器等领域。金属有机骨架材料(MOFs)是一类具有周期性网络结构的新型多孔晶体材料,在气体存储、气体分离、催化等领域具有重要的应用价值。近年来,以MOFs为前驱体制备多孔碳和多孔金属氧化物成为MOFs应用领域一个新的研究热点。本文主要综述了以MOFs为前驱体制备的多孔金属氧化物和多孔金属氧化物/碳复合物在CO氧化、催化产氢、异丁烷脱氢、环已烯氧化、醇直接氧化为酯、醛氧化酰胺化反应、光催化降解有机物和氧还原反应等方面的应用。     

超级电容器用石墨烯/金属氧化物复合材料

超级电容器是一种具有高功率密度和长循环寿命的新型储能装置,碳材料、金属氧化物和导电聚合物是常见的三种超级电容器电极材料。在石墨烯/金属氧化物复合材料中,石墨烯和金属氧化物可以发挥各自的优点,结合石墨烯优异的循环稳定性能和金属氧化物的高容量特性,纳米复合材料的综合性能可以得到很大地提升。因此,石墨烯/金属氧化物复合物的研究是超级电容器领域的热点研究方向之一。本文以金属氧化物的种类、石墨烯的结构和复合物的制备方法为线索,综述了国内外应用于超级电容器方面的石墨烯/金属氧化物复合材料的研究进展,归纳总结出与石墨烯复合最优的金属氧化物类型和制备方法,并进一步对该类复合材料的发展趋势进行了展望。     

MOFs材料制备方法的研究进展

金属有机框架材料(Metal Organic Frameworks, MOFs)是近二十年来发展迅速的一类以金属离子为中心、有机物为配体的新型自组装骨架材料,由于其具有多孔性、大比表面积、结构与功能的多样性等特点而被广泛研究。基于这些特性,MOFs材料在气体的吸附与分离、催化等领域具有广阔的应用前景。材料研究的第一步是材料的制备与合成,因此,对于MOFs制备方法的研究备受关注。本文综述了近年来新兴MOFs材料的制备方法,主要可分为"由下至上"法和"由上至下"法两大类,并对其发展趋势进行了展望。     

金属有机框架基复合材料的制备及其光热性能研究

金属有机框架材料(metal-organic frameworks, MOFs)是一类新型的有机-无机杂化材料, 具有可功能化的骨架结构、高比表面积、可调控的孔径尺寸等优势. 将MOFs与性质多样的有机/无机功能纳米材料复合, 不仅有可能充分发挥组分各自的优势, 而且有可能产生“1+1>2”的协同效应, 因而引起了人们的广泛关注. 具有光热效应的MOF复合物作为一类重要的MOF复合材料, 在生物诊疗、催化等领域展现出了良好的应用前景. 作者首先综述了近年来MOF复合材料的主要可控制备方法, 随后讨论了光热MOF复合材料的应用研究, 最后对该类材料的未来研究方向和挑战进行了展望.     

核壳结构金属-有机骨架及其衍生物在锂离子电池负极材料中的应用

金属–有机框架(MOFs)材料具有比表面积较大、孔径可调、制备容易、结构与功能多样性等优势,被广泛应用于电化学能源转化与储存领域。其中独特的核壳结构材料由于表面修饰的作用往往更能表现出核内与壳层的协同作用。本文介绍了具有核壳结构MOFs作为锂离子电池负极材料的发展现状,并重点综述其衍生物(多孔碳材料、金属氧化物、金属硫/硒化物以及金属/金属氧化物)的制备方法以及在锂离子电池负极中的应用。MOFs通过高温煅烧或改变化学反应条件的方法,可制备出结构可调的传统无机电极材料并表现出更优异的电化学性能。最后总结了核壳结构MOFs材料作为锂电负极材料存在的问题和挑战,并提出可能的解决途径和未来的应用前景。     

MOFs/水凝胶复合材料的制备及其应用研究

金属有机框架(MOFs)具有大量的孔隙结构和活性位点,在气体吸附、催化、医疗等领域均发挥了巨大的作用。MOFs是晶体粉末,具有脆性较大、在水中易分解和不易回收等缺点,从而限制了其应用。通过MOFs与柔性高分子的复合,特别是与水凝胶的复合,极大地改善了复合材料的柔顺性、可回收和可加工性等特性,进一步拓宽了MOFs的应用领域。本文详细阐述了基于水凝胶MOFs原位生成法、MOFs /水凝胶同时生成法和水凝胶包裹MOFs法等三种不同方法制备MOFs/水凝胶复合材料的研究进展,并对上述三种制备方法的特点及其产物特征进行了总结,进一步归纳了复合材料在生物医药、催化、废水处理和气体吸附等领域的应用。最后,对MOFs/水凝胶复合材料制备方法的改进和复合材料应用前景进行了深入讨论和展望。     

金属有机骨架复合材料在样品预处理中的研究进展

金属有机骨架（MOFs）材料是近几年涌现出的一类新型多功能多孔材料,以金属离子或金属簇为配位中心,与含氧或氮的有机配体通过配位作用形成多孔骨架结构。相比于其他传统无机多孔材料,MOFs具有比表面积高、孔隙率大、热稳定性好和结构与功能多样化的特点,因而被广泛用于气体存储、催化、吸附和分离等领域。MOFs复合材料在样品预处理方面的应用引起了研究者们的极大兴趣和广泛关注。由于MOFs材料和不同功能材料如高分子聚合物、碳基材料以及磁性材料组装复合,使MOFs复合材料的性能优于原来的MOFs材料。综述了近年MOFs复合材料在样品预处理的研究应用,尤其是在固相微萃取、固相萃取以及磁性固相萃取等方面的应用。     

金属有机骨架及其复合材料在分离领域中的应用进展

金属有机骨架（MOFs）是一类由无机金属离子与有机配体自组装形成的新型有机-无机杂化多孔材料,因具有比表面积超高、结构多样、热稳定性良好、孔道尺寸和性质可调等优势,在分离领域表现出重要的应用价值。然而,采用传统方法制备的MOFs多为粒径在微米或亚微米尺度的晶体,且颗粒形貌不规则,因此限制了MOFs在样品前处理和色谱固定相等领域的应用和发展。构建基于MOFs的复合材料是弥补MOFs应用缺陷的一项有效措施,有望在保留MOFs优越的分离特性的同时,引入基体材料的特定性能。该文简要综述了近年来MOFs及其复合材料在吸附、样品前处理和色谱固定相等分离领域中的应用进展,并对MOFs在分离科学中的应用前景做出展望。     

Metal Organic Framework Glasses: A New Platform for Electrocatalysis?

Metal organic framework (MOF) glasses are a coordination network of metal nodes and organic ligands as an undercooled frozen-in liquid, and have therefore broadened the potential of MOF materials in the fundamental research and application scenarios. On the road to deploying MOF glasses as electrocatalysts, it remains several basic scientific hurdles although MOF glasses not only inherit the structural merits of MOFs but also endow with active catalytic features including concentrated defects, metal centers and disorder structure etc. The research on the ionic conductivity, catalytic stability and reactivity of MOF glasses has yielded scientific insights towards its electrocatalytic applications. Here, we first comb the history, definition and basic properties of MOF glasses. Then, we identify the main synthetic methods and characterization techniques. Finally, we advance the potentials and challenges of MOF glasses as electrocatalysts in furthering the understanding of these themes.     

金属有机框架材料对Cr(Ⅵ)离子的吸附去除研究进展

重金属离子污染问题一直备受关注。开发利用多孔材料吸附去除水中重金属离子一直是材料、环境等相关学科领域的研究热点之一。金属有机框架材料(metal?organic frameworks,MOFs)是一类新型的多孔材料,具有结构多样、比表面积大、孔径可调、孔表面特征易设计调控等特点,在气体分离、催化、传感等领域表现出极大的应用潜力。近年来,高稳定MOF材料的构筑取得了许多重大突破,大量研究工作探索了这类材料在水中的应用,包括水中重金属离子的吸附去除。Cr(Ⅵ)离子是一类毒性大、分布广的重金属离子,不同条件下存在形态多样,其吸附去除研究具有理论和实际意义。本文主要综述了近年来利用MOF材料吸附去除水中Cr(Ⅵ)离子的研究工作,并将这些材料归属为:(1)高稳定的锆基MOF、(2)阳离子框架型MOF、(3)后修饰的MOF及(4)MOF基复合材料4类;也对这些材料的Cr(Ⅵ)离子吸附机理、吸附量、材料再生性等进行了概括;最后分析了MOF材料在重金属离子吸附去除实际应用上存在的问题并展望了今后的重点研究方向。     

Metal-organic framework growth at functional interfaces: thin films and composites for diverse applications

Porous metal-organic frameworks (MOFs) are highly ordered crystalline materials prepared by the self-assembly of metal ions with organic linkers to yield low density network structures of diverse topology. MOFs have attracted considerable attention over the last decade due to their facile preparation, tunable pore metrics and the ease of functionalisation of their internal surfaces, such that designer frameworks with exceptional properties for application in gas-storage, separation of small molecules, heterogeneous catalysis and drug delivery are becoming commonplace. For any material to find practical utility however, there is a need for processing and formulation into application-specific configurations. One way to do this is to prepare composite materials where the MOF is supported on a planar substrate or some other shaped body through interaction with functional groups at the support interface. This is a rapidly developing research area, and this review provides an overview of the diverse MOF composite materials prepared up to now, organised by interface type. The importance of the interface is explored within each section and while the overall emphasis is on applications of the composites, coatings and MOF-based devices, the most widely-used and successful synthetic strategies for composite formation are also presented. (183 references).     

Metal–Organic Framework (MOF)-Based Materials as Heterogeneous Catalysts for C−H Bond Activation

Converting light hydrocarbons such as methane, ethane, propane, and cyclohexane into value-added chemicals and fuel products by means of direct C−H functionalization is an attractive method in the petrochemical industry. As they emerge as a relatively new class of porous solid materials, metal–organic frameworks (MOFs) are appealing as single-site heterogeneous catalysts or catalytic supports for C−H bond activation. In contrast to the traditional microporous and mesoporous materials, MOFs feature high porosity, functional tunability, and molecular-level characterization for the study of structure–property relationships. These virtues make MOFs ideal platforms to develop catalysts for C−H activation with high catalytic activity, selectivity, and recyclability under relatively mild reaction conditions. This review highlights the research aimed at the implementation of MOFs as single-site heterogeneous catalysts for C−H bond activation. It provides insight into the rational design and synthesis of three types of stable MOF catalysts for C−H bond activation, that is, i) metal nodes as catalytic sites, ii) the incorporation of catalytic sites into organic struts, and iii) the incorporation of catalytically active guest species into pores of MOFs. Here, the rational design and synthesis of MOF catalysts that lead to the distinct catalytic property for C−H bond activation are discussed along with the post-synthesis of MOFs, intriguing functions with MOF catalysts, and microenvironments that lead to the distinct catalytic properties of MOF catalysts.     

Doubly Protective MOF-Photo-Fabrics: Facile Template-Free Synthesis of PCN-222-Textiles Enables Rapid Hydrolysis,Photo-Hydrolysis and Selective Oxidation of Multiple Chemical Warfare Agents and Simulants

New materials and chemical knowledge for improved personal protection are among the most pressing needs in the international community. Reported attacks using chemical warfare agents (CWAs,) including organophosphate soman (GD) and thioether mustard gas (HD) are driving research in field-deployable catalytic composites for rapid toxin degradation. In this work, we report simple template-free low temperature synthesis that enables for the first time, a deployable-structured catalytic metal-organic framework/polymer textile composite “MOF-fabric” showing rapid hydrolysis and oxidation of multiple active chemical warfare agents, GD and HD, respectively, and their simulants. Our method yields new zirconium–porphyrin based nano-crystalline PCN-222 MOF-fabrics with adjustable MOF loading and robust mechanical adhesion on low-cost nonwoven polypropylene fibers. Importantly, we describe quantitative kinetic analysis confirming that our MOF-fabrics are as effective as or better than analogous MOF powders for agent degradation, especially for oxidation. Faster oxidation using the MOF-fabrics is ascribed to the composite geometry, where active MOF catalysts are uniformly displayed on the MOF-textile enabling better reactant transport and reactive oxidant generation. Furthermore, we note the discovery of visible photo-activation of GD hydrolysis by a MOF-fabric, which is ascribed to oxidation at the active metal node site, significantly increasing the rate over that observed without illumination. These results provide important new insights into the design of future materials and chemical systems to protect military, first-responders, and civilians upon exposure to complex chemical toxins.     

动力锂离子电池正极材料磷酸钒锂制备方法

锂离子电池新型正极材料的开发是当前的研究热点,其中磷酸盐材料以其结构稳定、安全性能好及资源丰富等优点备受关注。磷酸钒锂理论能量密度可达500mWh/g,具有较高的电子离子导电性、理论充放电容量及充放电电压平台,被认为是一种极具竞争优势和应用前景的动力锂离子电池正极材料。传统磷酸钒锂合成方法有固相合成法、碳热还原法、溶胶凝胶法和水热合成法等,近年来,又出现了湿法固相配位法、微波固相合成法和流变相法等新型合成方法。本文简要介绍了磷酸钒锂的结构和性能特点,对磷酸钒锂制备方法的最新研究进展进行了较为全面的阐述,并详细介绍了本研究团队近年来在磷酸钒锂材料新型合成方法方面的探索成果。同时对各种合成方法的制备工艺及材料性能进行了对比分析,并探讨了当前存在的问题及未来的研究方向。     

Recent developments in the adsorptive removal of heavy metal ions using metal-organic frameworks and graphene-based adsorbents

Clean and potable water is a growing concern around the globe. Among the different water pollutants, heavy metal ions pose a serious health concern to all living beings. The quest for new adsorbents to remove heavy metal ions received a boost with the development in the field of metal-organic framework (MOF). The advancement in synthetic strategies and designing of MOF enabled the researchers to tune the adsorption characteristics and tailor the material specific to a heavy metal ion. Similar to MOF, graphene-based two-dimensional and three-dimensional materials are also promising due to the diverse functionalization possibilities and cost-effectiveness. There had been growing interest in applying MOF and graphene-based materials for the removal of heavy metal ions in the past decade. This review summarizes these developments in detail.     

An Overview of Metal-Organic Framework Based Electrocatalysts: Design and Synthesis for Electrochemical Hydrogen Evolution,Oxygen Evolution,and Carbon Dioxide Reduction Reactions

Due to the increasing global energy demands, scarce fossil fuel supplies, and environmental issues, the pursued goals of energy technologies are being sustainable, more efficient, accessible, and produce near zero greenhouse gas emissions. Electrochemical water splitting is considered as a highly viable and eco-friendly energy technology. Further, electrochemical carbon dioxide (CO₂) reduction reaction (CO₂RR) is a cleaner strategy for CO₂ utilization and conversion to stable energy (fuels). One of the critical issues in these cleaner technologies is the development of efficient and economical electrocatalyst. Among various materials, metal-organic frameworks (MOFs) are becoming increasingly popular because of their structural tunability, such as pre- and post- synthetic modifications, flexibility in ligand design and its functional groups, and incorporation of different metal nodes, that allows for the design of suitable MOFs with desired quality required for each process. In this review, the design of MOF was discussed for specific process together with different synthetic methods and their effects on the MOF properties. The MOFs as electrocatalysts were highlighted with their performances from the aspects of hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and electrochemical CO₂RR. Finally, the challenges and opportunities in this field are discussed.     

Potential Utilization of Metal–Organic Frameworks in Heterogeneous Catalysis: A Case Study of Hydrogen‐Bond Donating and Single‐Site Catalysis

Crystalline solid materials are platforms for the development of effective catalysts and have shown vast benefits at the frontiers between homogeneous and heterogeneous catalysts. Typically, these crystalline solid catalysts outperformed their homogeneous analogs due to their high stability, selectivity, better catalytic activity, reusability and recyclability in catalysis applications. This point of view, comprising significant features of a new class of porous crystalline materials termed as metal‐organic frameworks (MOFs) engendered the attractive pathway to synthesize functionalized heterogeneous MOF catalysts. The present review includes the recent research progress in developing both hydrogen‐bond donating (HBD) MOF catalysts and MOF‐supported single‐site catalysts (MSSCs). The first part deals with the novel designs of urea‐, thiourea‐ and squaramide‐containing MOF catalysts and study of their crucial role in HBD catalysis. In the second part, we discuss the important classification of MSSCs with existing examples and their use in desired catalytic reactions. In addition, we describe the relative catalytic efficiency of these MSSCs with their homogeneous and similarly reported analogs. The precise knowledge of discussed heterogeneous MOF catalysts in this review may open the door for new research advances in the field of MOF catalysis.     

Metal–Organic Frameworks Based Electrocatalysts for the Oxygen Reduction Reaction

In view of the clean and sustainable energy, metal–organic frameworks (MOFs) based materials, including pristine MOFs, MOF composites, and their derivatives are emerging as unique electrocatalysts for oxygen reduction reaction (ORR). Thanks to their tunable compositions and diverse structures, efficient MOF‐based materials provide new opportunities to accelerate the sluggish ORR at the cathode in fuel cells and metal–air batteries. This Minireview first provides some introduction of ORR and MOFs, followed by the classification of MOF‐based electrocatalysts towards ORR. Recent breakthroughs in engineering MOF‐based ORR electrocatalysts are highlighted with an emphasis on synthesis strategy, component, morphology, structure, electrocatalytic performance, and reaction mechanism. Finally, some current challenges and future perspectives for MOF‐based ORR electrocatalysts are also discussed.