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。     

金属有机骨架材料CuBDC的溶剂辅助重建

提出了一种简单而有效的重建被甲醇降解的对苯二甲酸铜(CuBDC)金属有机骨架材料的方法,只需溶剂辅助一步可实现CuBDC的重建。将CuBDC浸泡在甲醇溶液中使其降解,再用N,N-二甲基甲酰胺(DMF)重建,重建CuBDC孔隙率达到新制的94%,通过CO₂和环氧化合物的环加成反应评价重建CuBDC的催化性能,重建CuBDC的转化率和产率分别达到新制的97.8%和97.6%,实现了高度重建的目标,并具有良好的循环使用性能。利用扫描电子显微镜、X射线衍射仪、静态氮气吸附仪、热失重分析仪和傅里叶红外变换光谱仪等仪器表征,探讨了CuBDC降解-重建的机理。     

金属有机骨架材料在气体吸附与分离中的应用研究进展

金属有机骨架材料(MOFs)因具有超高比表面积、较大的孔隙率、多样化且可调的孔道结构及相对温和的制备条件等优势,目前已成为化学和材料等学科的研究热点之一。概述了MOFs材料的制备方法及其用于气体(含碳、含氮及含硫)吸附与分离方面的研究进展,并对其在该方面今后的发展趋势和应用前景进行了展望。     

金属有机骨架材料固定化酶的研究进展

金属有机骨架材料(MOFs)凭借其较高的比表面积和孔体积、可设计和调控的孔径及结构,以及化学和热稳定性等特点,克服了传统固定化酶载体的孔径尺寸不可控、制备成本高、酶浸出、产物稳定性差等不足,近年来成为一类新型酶固定化载体.首先,本文分类总结了MOFs固定化酶的合成策略,包括后合成包装和从头合成封装(仿生矿化、共沉淀和机械化学封装);然后进一步介绍了多级孔MOFs的孔道设计策略及其固定化酶体系.这种具备分级孔道结构的MOFs用于固定化酶既可以保证酶的较高负载率,又能提高酶催化底物的扩散速率;此外,本文还介绍了MOFs共固定化多酶体系及具有类酶特性的仿生MOFs固定化酶方面的研究.MOFs特有的孔道结构可以大大缩短酶与底物之间的扩散距离,同时充分利用了酶级联反应的中间产物,可以显著提高酶催化活性;文章最后总结了MOFs固定化酶复合材料在生物传感和污染物催化净化领域的主要应用,提出了MOFs固定化酶研究中的一些瓶颈问题,以期为该材料的进一步研究和未来产业化提供借鉴和参考.     

共价有机骨架储氢性能的研究进展

共价有机骨架(COFs)具有良好的热稳定性,大的表面积,高的孔隙率和极低的密度,因而显示出优异的储氢性能。重点介绍了COFs储氢性能的研究进展和目前存在的问题,提出了今后的研究重点和发展方向。     

金属有机框架材料在光催化还原CO2中的应用

人类依靠化石燃料来加速现代社会的发展,但化石燃料的过度消耗引发了一系列问题,如严峻的能源危机和环境恶化.例如化石燃料的大量使用导致大气中二氧化碳的含量逐年增加,成为全球温室效应的主要原因.在众多CO2减排的技术中,光催化还原CO2技术不仅可以减少大气中的CO2含量,而且还能通过太阳能将CO2光催化转化为有价值的化学物质,被认为是最有发展前景的技术之一.金属有机框架材料(Metal-organic frameworks,MOFs),也称为多孔配位聚合物,是具有周期性网状结构的三维多孔材料,由无机金属离子(或金属簇)和有机配体组成.MOFs具有大的比表面积、可调节的结构、丰富的催化活性位点、独特的电子能带结构,这些优点使其在光催化还原CO2反应中受到越来越多科研工作者的青睐,应用前景令人看好.目前,用于光催化还原CO2的MOFs材料主要包括单一MOFs光催化剂与基于MOFs的复合光催化剂两类.文章列举了具体实例来说明MOF基光催化材料在还原二氧化碳中的优势和独特性以及提高光催化活性的改进方法.本文归纳了近年来MOF基光催化剂在光催化还原CO2方面的研究进展,讨论了提高MOF基光催化剂(MOFs功能化、半导体/MOFs、光敏剂/MOFs、贵金属/MOFs)用于CO2还原性能的合理方法,探讨了基于MOFs的光催化剂用于CO2还原的挑战和展望.     

多级孔金属有机骨架材料的合成及应用研究进展

通过对目前多级孔金属有机骨架材料MOFs的合成方法及其在吸附、催化、传感领域应用进行介绍与总结,对多级孔MOFs材料的合成方法与应用前景进行评述与展望。     

金属有机骨架和共价有机骨架及其衍生物用于超级电容器电极材料的研究进展

金属有机骨架(MOFs)和共价有机骨架(COFs)是一系列结晶多孔材料.由于其高度有序的结构、高的表面积、可调的孔径和拓扑结构、富含氧化还原活性位点的连续骨架,MOFs和COFs及其衍生物在储能领域引起了广泛关注.为了制造高性能超级电容器电极,MOFs和COFs及其衍生物具有结构稳定性好、氧化还原活性位点丰富和电子导电...     

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。     

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。     

金属-有机骨架材料MOF-199对甲醛气体吸附行为的研究

初步探讨了金属-有机骨架材料MOF-199对甲醛气体的吸附性能.采用分光光度法测定MOF-199对甲醛气体的吸附量,研究了吸附量与吸附温度及吸附时间的关系,并探讨了MOF-199对甲醛的吸附机理,提出了一种测定MOF-199对甲醛吸附量的方法.结果表明,在50℃、6h的吸附条件下,MOF-199对甲醛气体的吸附量最大,达到83.84mg/g;MOF-199对甲醛气体具有较好的吸附效果.     

Metal-organic frameworks based materials for photocatalytic CO2 reduction

Photocatalytic conversion of CO₂ to valuable chemicals by solar irradiation is a hugely attractive process due to its potential to offset both the energy and economic penalties of CO₂ capture and sequestration. Metal-organic frameworks (MOFs) have recently been explored as photocatalysts for this processing owing to their promising photochemical and textural properties. Papers to date are collated and reviewed to highlight advances made in MOF photocatalysts through novel synthesis and analytical methods. These are compared with key metrics highlighting the range of materials and methods used to show the diversity and novelty of this emerging field. Knowledge gaps were noted in order to propose potential routes for further improvements in catalyst and reactor design.

This review was chosen as a runner up of the 2017 Materials Literature Review Prize of the Institute of Materials, Minerals and Mining, run by the Editorial Board of MST. Sponsorship of the prize by TWI Ltd is gratefully acknowledged     

Guest-Induced Multilevel Charge Transport Strategy for Developing Metal-Organic Frameworks to Boost Photocatalytic CO2 Reduction

Encapsulating photogenerated charge-hopping nodes and space transport bridges within metal–organic frameworks (MOFs) is a promising method of boosting the photocatalytic performance. Herein, this work embeds electron transfer media (9,10-bis(4-pyridyl)anthracene (BPAN)) in MOF cavities to build multi-level electron transfer paths. The MOF cavities are accurately regulated to investigate the significance of the multi-level electron transfer paths in the process of CO₂ photoreduction by evaluating the difference in the number of guest media. The prepared MOFs, {[Co(BPAN)(1,4-dicarboxybenzene)(H₂O)₂]·BPAN·2H₂O} and {[Co(BPAN)₂(4,4′-biphenyldicarboxylic acid)₂(H₂O)₂]·2BPAN·2H₂O} (denoted as BPAN-Co-1 and BPAN-Co-2), exhibit efficient visible-light-driven CO₂ conversion properties. The CO photoreduction efficacy of BPAN-Co-2 (5598 µmol g⁻¹ h⁻¹) is superior to that of most reported MOF-based catalysts. In addition, the enhanced CO₂ photoreduction ability is supported by density functional theory (DFT). This work illustrates the feasibility of realizing charge separation characteristics in MOF catalysts at the molecular level, and provides new insight for designing high-performance MOFs for artificial photosynthesis.     

Ligand-Assistant Iced Photocatalytic Reduction to Synthesize Atomically Dispersed Cu Implanted Metal-Organic Frameworks for Photo-Enhanced Uranium Extraction from Seawater

Uranium extraction from natural seawater is one of the most promising routes to address the shortage of uranium resources. By combination of ligand complexation and photocatalytic reduction, porous framework-based photocatalysts have been widely applied to uranium enrichment. However, their practical applicability is limited by poor photocatalytic activity and low adsorption capacity. Herein, atomically dispersed Cu implanted UiO-66-NH₂ (Cu SA@UiO-66-NH₂) photocatalysts are prepared via ligand-assistant iced photocatalytic reduction route. N—Cu–N moiety acts as an effective electron acceptor to potentially facilitate charge transfer kinetics. By contrast, there exist Cu sub-nanometer clusters by the typical liquid phase photoreduction, resulting in a relatively low photocatalytic activity. Cu SA@UiO-66-NH₂ adsorbents exhibit superior antibacterial ability and improved photoreduction conversion of the adsorbed U(VI) to insoluble U(IV), leading to a high uranium sorption capacity of 9.16 mg-U/g-Ads from natural seawater. This study provides new insight for enhancing uranium uptake by designing SA-mediated MOF photocatalysts.     

Electronic Modulation of Metal-Organic Frameworks Caused by Atomically Dispersed Ru for Efficient Hydrogen Evolution

Designing excellent electrocatalysts for the hydrogen evolution reaction (HER) is extremely significant in producing clean and sustainable hydrogen fuel. Herein, a rational strategy is developed to fabricate a promising electrocatalyst by introducing atomically dispersed Ru into a cobalt-based metal-organic framework (MOF), Co-BPDC (Co(bpdc)(H₂O)₂, BPDC: 4,4'-Biphenyldicarboxylic acid). The obtained CoRu-BPDC nanosheet arrays exhibit remarkable HER performance with an overpotential of 37 mV at a current density of 10 mA cm⁻² in alkaline media, which is superior to most of the MOF-based electrocatalysts and comparable to the commercial Pt/C. Synchrotron radiation-based X-ray absorption fine structure (XAFS) spectroscopy studies verify that the isolated Ru atoms are dispersed in Co-BPDC nanosheets with the formation of five-coordinated Ru-O₅ species. XAFS spectroscopy combined with density functional theory (DFT) calculations unravels that atomically dispersed Ru can modulate the electronic structure of the as-obtained Co-BPDC, contributing to the optimization of binding strength for H* and the enhancement of HER performance. This work opens a new avenue to rationally design highly-active single-atom modified MOF-based HER electrocatalysts via modulating electronic structures of MOF.     

Single-Atom Engineering of Covalent Organic Framework for Photocatalytic H2 Production Coupled with Benzylamine Oxidation

In photocatalysis, reducing the exciton binding energy and boosting the conversion of excitons into free charge carriers are vital to enhance photocatalytic activity. This work presents a facile strategy of engineering Pt single atoms on a 2D hydrazone-based covalent organic framework (TCOF) to promote H₂ production coupled with selective oxidation of benzylamine. The optimised TCOF-Pt SA photocatalyst with 3 wt% Pt single atom exhibited superior performance to TCOF and TCOF-supported Pt nanoparticle catalysts. The production rates of H₂ and N-benzylidenebenzylamine over TCOF-Pt SA3 are 12.6 and 10.9 times higher than those over TCOF, respectively. Empirical characterisation and theoretical simulation showed that the atomically dispersed Pt is stabilised on the TCOF support through the coordinated N₁-Pt-C₂ sites, thereby induing the local polarization and improving the dielectric constant to reach the low exciton binding energy. These phenomena led to the promotion of exciton dissociation into electrons and holes and the acceleration of the separation and transport of photoexcited charge carriers from bulk to the surface. This work provides new insights into the regulation of exciton effect for the design of advanced polymer photocatalysts.     

金属-有机骨架(MOFs)多孔材料的孔结构调节途径

多孔金属-有机骨架（MOFs）材料是近年来发展起来的一种新型功能材料.本文系统综述了MOFs孔结构的调节途径,包括构建分子调节、模板剂调节和反应环境调节控制.通过对有机配体的选择和修饰可调节MOFs的孔结构和孔表面的物理化学性质;而选择具有不同配位构型的金属离子也可以改变MOFs的骨架结构;模板剂通过控制骨架网络结构从而决定MOFs的孔径大小和形状;温度、溶剂等反应条件有时也会在一定程度上影响聚合物的结构.     

Utilizing Metal-Thiocatecholate Functionalized UiO-66 Framework for Photocatalytic Hydrogen Evolution Reaction

Exploiting clean energy is essential for sustainable development and sunlight-driven photocatalytic water splitting represents one of the most promising approaches toward this goal. Metal-organic frameworks (MOFs) are competent photocatalysts owing to their tailorable functionality, well-defined structure, and high porosity. Yet, the introduction of the unambiguous metal-centered active site into MOFs is still challenging since framework motifs capable of anchoring metal ions firmly are lacking. Herein, the assembly using 1,4-dicarboxylbenzene-2,3-dithiol (H₂ dcbdt ) and Zr-Oxo clusters to give a thiol-functionalized UiO-66 type framework,  UiO-66-dcbdt, is reported. The thiocatechols on the struts are allowed to capture transition metal (TM) ions to generate  UiO-66-dcbdt-M  ( M   = Fe, Ni, Cu) with unambiguous metal-thiocatecholate moieties for photocatalytic hydrogen evolution reaction (HER).  UiO-66-dcbdt-Cu  is found the best catalyst exhibiting an HER rate of 4.18 mmol g⁻¹ h⁻¹ upon irradiation with photosensitizing Ru-polypyridyl complex. To skip the use of the external sensitizer,  UiO-66-dcbdt-Cu  is heterojunctioned with titanium dioxide (TiO₂) and achieves an HER rate of 12.63 mmol g⁻¹ h⁻¹ (32.3 times that of primitive TiO₂). This work represents the first example of MOF assembly employing H₂ dcbdt  as the mere linker followed by chelation with TM ions and undoubtedly fuels the rational design of MOF photocatalysts bearing well-defined active sites.