金属有机框架材料对水体中有机污染物的吸附去除及氧化降解研究进展

随着水体环境中抗生素、内分泌干扰物及持久性有机物等大量新兴污染物的频繁检出,寻求高效、经济的污染物处理和治理技术迫在眉睫。金属有机框架(Metal organic frameworks, MOFs)材料是一类由金属离子或金属簇与有机配体结合的有机-无机杂化材料,具有孔隙率高、结构多样、孔径可调、配位点不饱和及功能可设计性强等特点,可广泛应用于有机污染物的吸附去除和氧化降解。本文综述了MOFs材料的合成方法及分类,阐述了其对水体中有机污染物的吸附和催化降解机理,探讨了温度、pH、MOFs浓度和离子强度等相关因素对MOFs材料去除污染物的影响,并对今后MOFs材料的研究方向进行了展望,以期为MOFs材料在环境污染修复领域的研究和应用提供理论基础。     

金属有机框架材料吸附重金属离子和放射性核素的研究进展

金属有机框架(MOFs)是一类无机-有机配位的多孔材料。与传统吸附剂相比，MOFs具有结构可设计性、功能多样性、比表面积大和孔隙率高等优点，可通过前合成和后修饰法调节孔径大小、引入特定官能团或活性位点，实现快速、高效地分离水中的重金属离子和放射性核素，对资源回收和环境修复意义重大。本文详述了MOFs吸附砷、铬和汞等重金属离子，吸附铀和锝等放射性核素的研究现状及作用机理，总结了提高MOFs吸附性能的方法，提出了MOFs作为重金属和放射性核素吸附剂时亟需解决的问题。     

金属有机骨架材料吸附去除水体中重金属研究进展

金属有机骨架(metal-organic frameworks,MOFs)是一类新型的有机-无机杂化多孔材料,由于其具有比表面积大、孔隙率高、孔径可调、结构多样、开放的金属位点和化学可修饰性等诸多优点在污染物吸附去除领域受到广泛的关注。通过总结近几年MOFs、MOFs复合材料和MOFs后修饰材料在水体中重金属离子的吸附去除方面的研究进展,并对其应用前景做出展望。     

金属有机骨架在水环境治理领域的应用

金属有机骨架(MOFs)由金属节点与有机配体通过配位键连接而成的多孔网络框架材料,其具有高比表面积和孔隙率以及丰富可调的孔结构,使其成为广泛关注的研究热点之一。对近几年来MOFs在水环境治理领域,特别是对重金属离子和有机污染物治理领域的研究进展进行了综述;讨论了MOFs通过构件分子和孔结构的修饰与调控对水中污染物的吸附机理;指出作为吸附剂MOFs最大的优越性在于,可根据目标污染物分子、离子的特点,在MOFs中引入不饱和金属位点和各种官能团和对骨架结构、孔隙大小和孔表面物理化学特性进行调控,以达到增大吸附选择性、增加吸附容量、提高吸附速率的目的,在吸附法去除重金属离子和有机污染物治理领域的有很大的潜力。同时,在合成MOFs时采用环境友好的构建分子,避免二次污染,并逐步降低成本。     

金属有机骨架材料及其在降解抗生素中的应用

抗生素作为治疗感染性疾病的药物，使用广泛且用量较大。由于抗生素的大量使用导致其通过直接或间接的途径进入水环境，进而造成水环境污染，对人体健康和生态环境造成危害。因此，基于新材料的吸附和降解技术用于去除水环境中的抗生素具有广泛的应用前景。金属有机骨架(MOFs)是一种新型多孔材料，具有比表面积大、可控性高、可修饰的特点，可选择性、高效地去除水环境中的抗生素。总结了MOFs的合成方式和性质特点，阐述了水环境中抗生素的吸附和催化降解的应用及机理。最后，总结了MOFs材料在水环境中抗生素吸附和催化降解应用中遇到的挑战，并对其应用前景进行了展望。     

MOFs基材料对金属离子吸附分离的研究进展

金属有机框架(MOFs)基功能材料在金属离子吸附等方面具有重要的应用价值和前景。通过表面改性或功能化MOFs可得到对不同离子响应的高效吸附材料，这种响应是依靠MOFs材料的本身优良属性或与改性材料之间的协同作用，进而充分发挥各组分的优势实现不同金属离子的吸附分离。介绍了MOF基吸附材料的类型、制备方法以及其对金属离子吸附的研究进展，并对功能化的MOFs材料的研究方向进行了展望。     

MOFs作为防毒面具中吸附材料的应用研究

金属有机骨架材料(MOFs)是由金属离子与有机配体自组装而成的结构规整的多孔骨架材料,其巨大的比表面积使其在有毒气体分子吸附等领域有着广泛应用。可以通过对MOFs材料中有机配体进行酸、碱修饰,增加气体与材料骨架之间的相互作用,提高对有毒气体的吸附选择性及吸附容量。简单介绍了MOFs材料的多样性,分类总结了MOFs材料作为防毒面具中吸附材料对酸性、碱性及中性有毒气体的吸附性能。最后,对MOFs材料作为防毒面具吸附材料的应用前景进行了展望,宽范围、高吸附容量的MOFs材料是用于防毒面具中的理想吸附材料,是今后吸附材料研究的重点方向。     

金属有机骨架材料对生物燃料的吸附和纯化性能研究

金属有机骨架(MOFs)材料由于具有表面积大、结构多样性、永久孔隙率高和热稳定性高等优点,广泛应用于存储、分离和催化等领域。生物燃料是对环境无害且呈碳中性的一类新型可再生能源。主要介绍了研究MOFs吸附与分离性能的理论方法,综述了有关MOFs在生物燃料吸附与分离性能领域的实验和理论方面的最新进展,分析了提高吸附和纯化性能的方法和途径。最后讨论了MOFs在生物燃料领域未来的研究方向和发展前景。     

三元水滑石负载的硫化纳米零价铁对铀的高效去除与机理研究

纳米零价铁材料(NZVI)被广泛用于环境中放射性核素U(VI)的去除, 但是单纯的NZVI存在稳定性差、去除效果差等不足。本研究结合表面钝化技术与负载技术制备得到Ca-Mg-Al水滑石负载的硫化纳米零价铁材料(CMAL-SNZVI), 并将其用于U(VI)的高效去除。结合宏观试验与光谱分析表征得到的结果表明, CMAL-SNZVI材料具有出色的理化性质与较高的活性, 对水溶液中U(VI)的去除具有优良的效果, 在2 h内可以达到反应平衡, 且最大吸附量可达175.7 mg·g ^-1。CMAL-SNZVI对U(VI)的去除主要是由吸附过程与氧化还原反应相结合的方式: 吸附过程中U(VI)与材料中的CMAL基底、SNZVI的表层通过内层表面络合作用结合; 还原过程中材料的NZVI内核将U(VI)还原成低毒难溶的U(IV)后去除。CMAL-SNZVI可为NZVI材料的改性方法提供新的研究方向, 同时, CMAL-SNZVI在污染物去除方面表现优异, 可以作为出色的环境修复材料。     

UiO-66系列材料在CO_2吸附存储与分离中的应用研究进展

金属有机框架(MOFs)是一种由金属离子或金属簇和有机配体自组装形成的三维多孔材料。由于大部分MOFs材料的物理化学稳定性较差,极大地限制了其在气体吸附与分离中的应用。UiO-66系列材料具有出色的水热稳定性和化学稳定性,是目前报道的MOFs材料中稳定性最好的材料之一。介绍了UiO-66系列材料用于吸附与分离CO_2所取得的突破性进展以及材料的改性方法,指出了该材料在结构优化和性能研究方面存在的问题,展望了UiO-66系列材料在能源和环境中的应用前景。     

Mechanochemistry: Toward green synthesis of metal–organic frameworks

Metal–organic frameworks (MOFs) have attracted a special attention due to outstanding porosity, adjustable pore sizes, and huge opportunities in varying organic–inorganic compositions. Enormous studies conducted so far on MOFs indicate their high potential in catalysis, gas adsorption, drug delivery, water treatment, energy storage, among others. However, mass production of MOFs is still limited mainly due to the non-economic, non-green and complex synthesis methods. Mechanochemistry is an alternative solution for efficient and environmentally friendly syntheses of various MOFs. Fast and solvent-free or solvent-less mechanosynthesis seems to be a very powerful versatile method for obtaining these advanced porous materials. The mechanochemical concept was used for the preparation of various MOFs including the most popular structures: MOF-5, ZIF-8, HKUST-1, MIL-101, UiO-66. These MOFs feature high specific surface areas, comparable to those prepared by conventional solvent-based methods. Furthermore, mechanochemistry was successfully used for the synthesis of non-conventional multimetallic MOFs and previously unreported solid phases. This review shows the recent developments, challenges and perspectives of green synthesis of diverse MOF structures using mechanochemistry. Besides describing the mechanochemical synthesis of MOFs, some achievements in green applications are also summarized. Importantly, current trends in research suggests for further development of these fields i.e., harmful gas adsorption, water treatment, and energy storage.     

Distribution of artificial radionuclides in lacustrine sediments in China

Establishing accurate historical records of the distribution, inventory and source of artificial radionuclides in the environment is important for environmental monitoring and radiological health protection due to their potential toxicity, and is also useful for identification and risk assessment of possible future environmental inputs of radionuclides from nuclear weapons tests and accidental release from the nuclear fuel reprocessing facilities or nuclear power reactors. A sector-field inductively coupled plasma mass spectrometer was used to study the recent sedimentation of Pu isotopes in 11 lakes in China. The distribution of (137)Cs was investigated using the conventional radiometric analytical methods. Based on the isotopic compositions of Pu and the activity ratio of (137)Cs/(239+240)Pu, the sources of artificial radionuclides were identified. The potential applications of Pu isotopes for sediment dating and for regional and global environmental change studies were discussed.     

Direct high-resolution alpha spectrometry from nuclear fuel particles in an outdoor air sample

The potential use of direct high-resolution alpha spectrometry to identify the presence of transactinium elements in air samples is illustrated in the case when alpha-particle-emitting radionuclides are incorporated in nuclear fuel particles. Alpha particle energy spectra are generated through Monte Carlo simulations assuming a nuclide composition similar to RBMK (Chernobyl) nuclear fuel. The major alpha-particle-emitting radionuclides, in terms of activity, are 242Cm, 239Pu and 240Pu. The characteristics of the alpha peaks are determined by fuel particle properties as well as the type of the air filter. It is shown that direct alpha spectrometry can be readily applied to membrane filter samples containing nuclear fuel particles when rapid nuclide identification is of relevance. However, the development of a novel spectrum analysis code is a prerequisite for unfolding complex alpha spectra.     

金属有机骨架材料质子传导的研究进展

金属有机骨架材料(MOFs)由于其结构多样性、骨架的可修饰性、超高比表面积和孔隙等特点,在质子传导、气体分离和吸附、催化、化学传感和生物医药领域有着独特的优势和广泛的应用。本文综述了近年来金属有机骨架材料在质子传导方面的研究进展,系统地阐述了质子传导的Grotthuss机理和Vehicel机理,并针对两种不同的机理分别总结了提高MOFs质子传导率的方法,对质子传导MOFs的设计具有显著的指导意义。此外,还介绍了质子传导MOFs最重要的应用之一——质子交换膜。质子交换膜由于其高电导率、易成膜以及优良的选择性透过等特点在燃料电池上有巨大的应用潜力。质子交换膜燃料电池的快速发展,可改善对化石燃料高度依赖的能源结构和日益恶化的环境问题。     

基于金属有机框架的光子晶体制备与应用研究进展

近年来,基于光子晶体优异的光学性能和金属有机框架(MOFs)特殊的多孔结构,使基于MOFs的光子晶体研究备受研究者们的关注。本文综述了近年来MOFs材料及其在光子晶体中的应用研究进展。首先简单介绍了MOFs和光子晶体的基本概况及MOFs与光子晶体相结合的优势,然后阐述了基于MOFs的光子晶体的制备方法,进一步概括了其应用现状,并总结了当前基于MOFs的光子晶体研究所存在的困境,最后展望了其未来的发展方向。这些工作为MOFs材料在光子晶体中的实际应用提供了策略支撑。      

金属有机框架材料载体系统在食品抗菌包装中的应用

目的 综述金属有机框架材料(Metal-organic frameworks,MOFs)作为载体系统在食品抗菌包装领域的研究现状和应用进展,以期为MOFs类抗菌包装材料的研发和应用提供参考。方法 介绍MOFs的基本概念及分类,概述MOFs的制备方法(加热法、机械法和电化学法等),总结归纳近年来MOFs作为载体系统在无机抗菌剂、有机抗菌剂和天然抗菌剂领域的应用,并讨论MOFs作为载体系统的机遇和挑战。结论 MOFs作为一种有机与无机相结合的多孔性复合材料,不仅可有效封装抗菌剂,实现缓释和控释,且将MOFs复合材料作为高分子填料可提高其抗菌性能、力学性能和抗紫外线性能等,因此在制备高效、安全的食品抗菌包装方面具有巨大潜力。     

A carbon composite based on pyrolyzed diphthalocyanines for immobilization of high-level waste from nuclear industry

A new procedure for immobilization of high-level waste from spent nuclear fuel (SNF) of nuclear power plants (NPP) is suggested. The HLW immobilization process consists in the radionuclide transfer into the form of acetates, followed by synthesis of their diphthalocyanines and their subsequent pyrolysis in an inert medium. Real raffinate solutions from reprocessing of SNF of Novovoronezh NPP were used as HLW. The efficiency of the immobilization of radionuclides (mainly REE and minor actinides) was found to be higher than 99%. The thermal stability, chemical durability (leaching with aqueous solutions with pH from 2 to 9), and radiation resistance of the samples were evaluated using α-, β-, and γ-ray spectrometry. The evolution of the structure of the pyrolyzed diphthalocyanines in the temperature range 800–1600°C was studied by small-angle neutron scattering, X-ray diffraction analysis, and atomic force microscopy. The results obtained have confirmed the hypothesis that the pyrolysis of diphthalocyanines yields a branched network of carbon atom nanoclustes of size from 5 to ~150 nm, ensuring efficient retention of radionuclides in the host material. The host material is comparable in the thermal stability, i.e., in the degree of radionuclide retention at 1000–1200°С, with borosilicate or phosphate glasses, which are the most widely used host materials for radioactive waste immobilization, and considerably surpasses them in the resistance to leaching and radiation.     

Selection of fuel cladding material for nuclear fission reactors

The growing understanding of the link between carbon emissions and global warming has been promoting a discussion on the environmental and safety viability of nuclear power generation. Current open fuel cycle reactors, however, result in low energy efficiency and produce large volumes of nuclear waste. More advanced nuclear reactors, which are currently under investigation, are expected to allow more efficient and safer use of nuclear energy. In all these cases, the fuel cladding is the most important safety barrier in fission nuclear reactors, as it restrains most of the radioactive fission products within its volume. The selection of fuel cladding material is based on many design constraints, such as neutron absorption cross section, service temperature, mechanical strength, toughness, neutron radiation resistance, thermal expansion, thermal conductivity, and chemical compatibility. The present paper reviews the selection of nuclear fuel cladding materials since the early reactors, illustrating some of the main failure modes and briefly discussing the challenges facing the development of fuel cladding materials for generation IV reactors.     

锆合金涂层包壳专利申请态势全景分析

事故容错燃料(ATF)是日本福岛核事故之后提出的新一代核燃料概念,主要是为了提高反应堆在事故工况下的容错性能,从根本上提高核电厂对严重事故的抵御能力,从而有效地提高核电的安全性和经济性。针对传统核燃料使用的锆合金包壳,通过外表面涂层改性的方法提高其在事故工况下的抗高温氧化性能是事故容错燃料的主要研究方向。为了对锆合金涂层包壳的技术发展现状和趋势进行全面了解,对该技术相关的国际及国内专利申请态势进行了统计分析,研究了该领域的专利申请发展态势、专利来源地区及布局地区特点,重点分析了自20世纪60年代以来锆合金涂层包壳技术分支发展趋势;此外,结合我国的锆合金涂层包壳的研究现状,从研究进展及技术聚焦等方面提出锆合金涂层包壳研发建议。     

新型铋基SiOCNF复合膜对放射性气态碘的吸附性能

放射性碘是典型的核裂变产物之一, 吸附-分离-固化放射性碘(¹²⁹I、¹³¹I等)对于核电运营、乏燃料后处理具有重要意义。本研究采用静电纺丝技术和热还原方法, 以一种聚甲基倍半硅氧烷树脂(MK树脂)为原料, 成功制备出一种新型铋基复合纳米纤维膜(Bi@SiOCNF)。该材料以SiOC纤维为基体, 金属单质铋负载在SiOCNF表面与三维网络空间, 对气体碘表现出良好的捕获与固定能力。吸附实验结果表明, 该材料在2 h内可达到最大饱和吸附容量(515.2 mg/g)。XRD、XPS等测试结果表明, 铋基SiOCNF复合纳米纤维膜通过化学吸附与物理吸附机制共同吸附气态碘。热分析表明, Bi@SiOCNF具有良好的热稳定性。该材料在核电站、乏燃料后处理厂对放射性气态碘的捕获、固定和储存等方面具有潜在的应用前景。