2D Metal-Organic Frameworks for Electrochemical Energy Storage

Metal-organic frameworks(MOFs)have been widely adopted in various fields(catalysis,sensor,energy storage,etc.)during the last decade owing to the trait of abundant surface chemistry,porous structure,easy-to-adjust pore size,and diverse functional groups.However,the limited active sites and the poor conductivity hinder the relative practical application.2D MOFs can shorten the ion transport path with the merit of layered structure.The large surface area can increase the number of active sites as well as effectively utilize the sufficient active sites,exhibiting enormous potential in the field of energy storage systems(EESs).In this review,the characteristics of the 2D MOFs have been introduced,and the systematic synthesis methods(top-down and bottom-up)of 2D MOFs are presented,providing fundamental understanding for the construction of 2D MOFs.Moreover,the applications of 2D MOFs in energy storage fields such as supercapacitors and batteries are demonstrated in detail.Finally,the future development prospects have been proposed,offering guidelines for the rational utilization of 2D MOFs and promoting the understanding of 2D MOFs in EESs.

Novel green-fruit detection algorithm based on D2D framework

In the complex orchard environment,the efficient and accurate detection of object fruit is the basic requirement to realize the orchard yield measurement and automatic harvesting.Sometimes it is hard to differentiate between the object fruits and the background because of the similar color,and it is challenging due to the ambient light and camera angle by which the photos have been taken.These problems make it hard to detect green fruits in orchard environments.In this study,a two-stage dense to detection framework(D2D)was proposed to detect green fruits in orchard environments.The proposed model was based on multi-scale feature extraction of target fruit by using feature pyramid networks MobileNetV2+FPN structure and generated region proposal of target fruit by using Region Proposal Network(RPN)structure.In the regression branch,the offset of each local feature was calculated,and the positive and negative samples of the region proposals were predicted by a binary mask prediction to reduce the interference of the background to the prediction box.In the classification branch,features were extracted from each sub-region of the region proposal,and features with distinguishing information were obtained through adaptive weighted pooling to achieve accurate classification.The new proposed model adopted an anchor-free frame design,which improves the generalization ability,makes the model more robust,and reduces the storage requirements.The experimental results of persimmon and green apple datasets show that the new model has the best detection performance,which can provide theoretical reference for other green object detection.

Ultrathin 2D Metal–Organic Framework Nanosheets In situ Interpenetrated by Functional CNTs for Hybrid Energy Storage Device

The controllable construction of two-dimensional(2D)metal–organic framework(MOF)nanosheets with favorable electrochemical performances is greatly challenging for energy storage.Here,we design an in situ induced growth strategy to construct the ultrathin carboxylated carbon nanotubes(C-CNTs)interpenetrated nickel MOF(Ni-MOF/C-CNTs)nanosheets.The deliberate thickness and specific surface area of novel 2D hybrid nanosheets can be effectively tuned via finely controlling C-CNTs involvement.Due to the unique microstructure,the integrated 2D hybrid nanosheets are endowed with plentiful electroactive sites to promote the electrochemical performances greatly.The prepared Ni-MOF/C-CNTs nanosheets exhibit superior specific capacity of 680 C g^−1 at 1 A g^−1 and good capacity retention.The assembled hybrid device demonstrated the maximum energy density of 44.4 Wh kg^−1 at a power density of 440 W kg^−1.Our novel strategy to construct ultrathin 2D MOF with unique properties can be extended to synthesize various MOF-based functional materials for diverse applications.

全共轭二维有机框架材料在有机电子器件中的应用

有机电子器件已成为当今社会与工业中不可或缺的组成部分,在显示、通讯、能源和环境等方面都具有广泛的应用。有机电子器件的核心是有机半导体材料,开发具有高电荷传输特性的有机半导体材料是提升有机电子器件性能的关键。作为材料领域的研究前沿,有机多孔晶态材料由于具有确定的化学结构、功能可设计性、大的比表面积、高的孔隙率以及结构可修饰性等特征吸引了广泛的研究,在众多领域都展现出了广阔的应用前景。其中,由于具有高的结构平面性、电子离域性、电荷传输性质以及化学稳定性,全共轭二维有机框架材料作为有机电子学中的载流子传输材料受到广泛关注。当前,人们基于不同结构与功能的全共轭二维有机框架材料,构筑了多种有机电子器件并展现出了巨大的应用潜力。本文首先介绍目前发展的全共轭二维有机框架材料的主要结构,随后重点综述全共轭二维有机框架材料在有机电子器件包括有机场效应晶体管、有机光电探测器、有机光伏电池、化学阻抗传感器及一些新兴电子器件中的最新研究进展。最后阐述实现全共轭二维有机框架材料在有机电子器件的实际应用中所面临的挑战并提出了未来的研究方向。

Metal and ligand modification modulates the electrocatalytic HER,OER,and ORR activity of 2D conductive metal-organic frameworks

It is highly desirable to design efficient and stable hydrogen evolution reaction(HER)and oxygen evolution/reduction reaction(OER/ORR)electrocatalysts for the development of renewable energy technologies.Herein,density functional theory(DFT)calculations were conducted to systematically investigate a series of TMN_(x)O_(4-x)-HTT(TM=Fe,Co,Ni,Ru,Rh,Pd,Ir and Pt;HTT=hexahydroxy tetraazanaphthotetraphene)analogs of two-dimensional(2D)conductive metal-organic frameworks(MOFs)as potential electrocatalysts for the HER,OER and ORR.The thermodynamic and electrochemical stability simulations suggest that these designed catalysts are stable.Remarkably,CoO_(4)-HTT,RhN_(3)O_(1)-HTT and IrN3O1-HTT are predicted to be the most promising catalysts for the HER,OER and ORR,respectively,surpassing the catalytic activity of corresponding benchmark catalysts.The volcano plots were established based on the scaling relationship of adsorption Gibbs free energy of intermediates.The results reveal that regulating combinations of metal active centers and local coordination environments could effectively balance the interaction strength between intermediates and catalysts,thus achieving optimal catalytic activity.Our findings not only opt for the promising HER/OER/ORR electrocatalysts but also guide the design of efficient electrocatalysts based on 2D MOFs materials.

基于GDI的2D游戏框架设计

2D游戏具有很大的应用前景。游戏软件是一种复杂度较高的软件,利用游戏框架可以降低游戏开发难度,提高游戏开发效率,因此设计2D游戏框架具有现实的意义。该文探讨了框架的概念,分析了2D游戏软件开发的特征,从中总结出2D游戏框架需要实现的功能,结合Windows的图形设备接口(GDI),提供了一个2D游戏框架的设计,其中实现了精灵创建、释放、渲染、资源管理、帧频锁定、事件传递等2D游戏中必需的功能,并留出了可扩展的接口。该文最后给出了框架的使用方法。

Tuning the reversible chemisorption of hydroxyl ions to promote the electrocatalysis on ultrathin metal-organic framework nanosheets

Interfacial engineering to alter the configuration of active sites in heterogeneous catalysts is a potential strategy for activity enhancement,but it remains unelucidated for metal-organic frameworks(MOFs).Here,we demonstrate that the surface of two-dimensional Co-based MOF is modified by decorating Ag quantum dots(QDs)simply through in-situ reduction of Ag+ions.Toward oxygen evolution reaction(OER),it reveals that the catalysis is mediated by the reversible redox of Co sites between Co^(3+) and Co^(4+) states coupling with transfer of OHions.The decoration of Ag QDs decreases the redox potential of Co sites,and thus effectively decreases the overpotential of OER.The TOFs of Co sites are increased by 77 times to reach 5.4 s^(-1) at an overpotential of 0.35 V.We attribute the activity enhancement to the tuning of the coupling process between Co sites and OHions during the redox of Co sites by Ag QDs decoration based on Pourbaix analysis.

One New 3D Pillared-layer Ag(Ⅰ)-Coordination Framework Based on a Unique 1D Ag2O2 Ribbon： Synthesis,Crystal Structure and Luminescent Properties

A new 3D Ag（I） coordination polymer {[Ag（AZDB）（0.5）（bpe）（0.5）]·H2O}n（1） has been papared by azobenzene-3,3？-dicarboxylicate（H2AZDB）, 1,2-bis（4-pyridyl）ethylene（bpe） and silver salts via hydrothermal method. The compound was fully characterized by single-crystal X-ray diffraction, elemental analyses, infrared spectrum（IR）, powder X-ray diffraction（PXRD） and thermogravimetric analysis（TGA）. The strucrural analysis indicate that compound 1 shows a 3D pillared-layer framework constructed from a unique 1D Ag2O2 ribbon and pyridyl/carboxylicate mixed system, which features a 2-nodal（4, 6）-connected fsc net with a（4^4·6^10·8）（4^4·6^2） topology.Moreover, the photoluminescent properties have also been discussed.

二维MOF-5/PVDF复合膜的制备及其在重金属离子Cu^(2+)吸附中的应用

采用非溶剂诱导相分离法制备二维MOF-5/聚偏氟乙烯(PVDF)复合膜,然后将其用于吸附重金属离子Cu^(2+)。分析MOF-5的形貌、结构和晶型,优化MOF-5/PVDF复合膜的制备工艺参数,并探究最优性能复合膜的可重复使用性能。结果表明:制备的二维MOF-5大小均一、呈明显的薄片状;当MOF-5含量为8%与10%时,复合膜表现出良好的Cu^(2+)去除能力;经过7次循环试验后,复合膜依旧能够保持较好的吸附性能,表现出良好的可重复使用性能。制备了对铜离子具有良好吸附性能的二维MOF-5/PVDF复合膜,并实现了膜的可重复使用。

高效光催化金属有机框架(MOFs)的构筑策略

面对全球能源短缺和环境污染等问题,发展绿色、可持续的能源来替代传统的化石能源成为迫切需求.太阳能作为一种清洁可再生能源,其有效转化与利用受到了广泛关注.光催化将太阳能转化为化学能,其核心是新型高效的光催化材料.金属有机框架材料(MOFs),是一类由金属或金属节点与多齿有机配体相互连接而成的微介孔材料,具有独特的组成结构和特性,有望成为有应用前景的光催化材料.目前已有一些关于MOFs基光催化的综述,但考虑到该领域在过去几年迅速发展,为了研发高效的MOFs基光催化材料,非常有必要对已经报道的用于提高MOFs基光催化剂性能的策略进行总结.本综述重点总结了已报道的通过调控MOFs基材料的组成和结构的策略来提升其光催化性能的最新研究进展.首先,简要介绍了MOFs基材料的结构特点及其在光催化领域应用的优势,阐述了MOFs基材料光催化的基本原理,提出了影响其光催化性能的关键因素,包括光吸收能力、光生载流子的分离和迁移以及催化活性位点.其次,阐明不同结构调控策略通过优化关键因素进而提高光催化性能的原理,具体包括MOFs基材料中金属掺杂、配体功能化、超薄二维材料构筑以及缺陷工程策略.然后,通过总结典型案例,详细讨论了上述策略如何通过调控MOFs基材料的组成和结构来优化关键因素,从而提高MOFs基材料的光催化性能.最后,针对MOFs基材料光催化所面临的机遇、挑战及其发展趋势提出展望:(1)影响MOFs基光催化剂效率的因素是多方面的,因此将不同策略相结合有利于更好地提高MOFs基光催化剂的性能.除了本文总结的四种构筑策略,最近其它一些关于提升MOFs基材料光催化性能的结构调控策略也有零星报道,如微环境调控、晶面工程等,也值得进一步关注.(2)与无机半导体光催化剂相比,MOFs基材料的结构稳定性较差,因此应特别注意其在光催化条件下的稳定性,特别是MOFs基材料在水中的反应体系.(3)先进原位表征技术的发展和理论研究的深化对于高效MOF基光催化系统的设计及机理研究至关重要.(4)MOFs基材料的多功能性可以使其作为光诱导一锅多步反应的多功能催化材料,应大力开展研究.综上,本文系统地总结了通过调控MOFs基材料的组成和结构从而达到提升其光催化性能的不同策略,并就MOFs基材料光催化所面临的机遇、挑战及其发展趋势提出展望.希望本文能够为深入了解MOFs基光催化体系中组成-结构-性能关系以及从原子水平来设计研发高效的MOFs基光催化剂提供参考.

Customizable 2D Covalent Organic Frameworks for Optoelec-tronic Applications

2D covalent organic framework(2D-COF),a modular three-dimensional material,is easily influenced by the component module.The assembly of different functionalized modules gives 2D-COF unique performance.The modular structure not only allows for customi-zation but also allows for variety,which gives 2D-COF a wide range of functions.Hence,many building blocks with catalytic,ligand,semiconductor,luminescent,and redox centers are integrated into the COF scaffold.The connection and assembly of such modules determine the nature of the final block material.The intra-layer connections of the modules form a monolayer mesh chemical structure,and the subsequent stacking of the monolayer mesh structure produces the final crystalline porous material-2D-COF.This review describes in detail the potential of COF materials as optoelectronic materials and our understanding of optoelectronic processes,starting from monolayer reticulation chemistry to final 3D stacked structures,thus establishing a new paradigm for the ra-tional design of well-defined novel 2D-COF optoelectronic materials and devices.

Modulated noble metal/2D MOF heterostructures for improved hydrogen storage of MgH_(2)

The conjugation of external species with twodimensional(2D)materials has broad application prospects.In this study,we have explored the potential of noble metal/2D MOF heterostructures in hydrogen storage.Specifically,the MgH_(2)-Ni-MOF@Pd system has shown remarkable hydrogen desorption/sorption performances,starting to liberate hydrogen at 1810C,which is 2300C lower than that of pristine MgH2.Under the catalytic effect of Ni-MOF@Pd,the dehydrogenation apparent activation energy of MgH2 is noticeably decreased from(133.5±17.5)to(34.58±1.87)kJ·moL^(-1),and the hydrogenation apparent activation energy is reduced from(70.41±7.43)to(25.78±4.64)kJ·moL^(-1),which is lowered by 63.4%.The fully-dehydrogenated MgH2-NiMOF@Pd composite rapidly uptakes hydrogen,with 2.62wt%at 100℃and 6.06 wt%at 150℃within 300 s,respectively.The mechanism analysis of MgH2 catalyzed by Ni-MOF@Pd has revealed that the transformation of Mg_2Ni and Mg_2NiH_4 could act as a"hydrogen pump",providing numerous channels for fast diffusion and transport of hydrogen atoms.Moreover,in the dehydrogenation process,the element Pd reacts with MgH_(2)to form the MgPd alloy phase,which makes MgH_(2)take precedence to decompose through the Mg-Pd alloy rather than self-decomposition,further reducing thermal stability and improving de/hydrogenation kinetics.The synergistic effect of Mg-Pd,Mg_2Ni,and the special ultra-thin 2D sheet structure of the additive is the main reason for the good hydrogen storage property of MgH_(2)-Ni-MOF@Pd.Our findings provide inspiration for designing efficient multifunctional additives with unique morphologies to optimize the hydrogen desorption/sorption behaviors of hydrogen storage materials.

Flexible interdigitated layered framework with multiple accessible active sites for high-performance CH_(3)I capture

The development of adsorbent materials for effective capture of radioactive iodomethane(CH_(3)I) from the off-gas of used nuclear fuel reprocessing, remains a significant and challenging line of research because currently state-of-art adsorbents still suffer from low binding affinity with CH_(3)I. Here, we proposed a brand-new adsorption topological structure by developing a 2D interdigitated layered framework, named SCU-20, featuring slide-like channel with multiple active sites for CH_(3)I capture. The responsive rotating-adaptive aperture of SCU-20 enables the optimal utilization of all active sites within the pore for highly selective recognition and capture of CH_(3)I. A record-breaking CH_(3)I uptake capacity of 1.84 g/g was achieved under static sorption conditions with saturated CH_(3)I vapor. Both experimental and theoretical findings demonstrated that the exceptional uptake of SCU-20 towards CH_(3)I can be attributed to the confined physical electrostatic adsorption of F sites, coupled with the chemical nitrogen methylation reaction with uncoordinated N atoms of pyrazine. Moreover, dynamic CH_(3)I uptake capacity potentially allows for the capture of CH_(3)I in simulated real-world off gas reprocessing conditions. This study highlights the potential of SCU-20 as a promising candidate for efficient capture of iodine species and contributes to the development of effective solutions for radioactive iodine remediation.

Modulation mechanism of electron energy dissipation on superlubricity based on fluorinated 2D ZIFs

Electron energy dissipation is an important energy dissipation pathway that cannot be ignored in friction process.Two-dimensional zeolite imidazole frameworks(2D ZIFs)and fluorine doping strategies give 2D Zn-ZIF and 2D Co-ZIF unique electrical properties,making them ideal materials for studying electron energy dissipation mechanism.In this paper,based on the superlubricity modulation of 2D fluoridated ZIFs,the optimal tribological properties are obtained on the 2D F-Co-ZIF surface,with the friction coefficient as low as 0.0010.Electrical experiments,density functional theory(DFT)simulation,and fluorescence detection are used to explain the mechanism of fluorine doping regulation of tribological properties from the two stages,namely energy transfer and energy release.Specifically,the energy will transfer into the friction system through the generation of electron–hole pairs under an external excitation,and release by radiation and non-radiation energy dissipation channels.Fluorination reduces energy transfer by altering the electronic properties and band structures of ZIFs,and slows down the charge transfer by enhancing the shielding efficiency,thus slowing the non-radiative energy dissipation rate during the energy release stage.Our insights not only help us better understand the role of fluorine doping in improving tribological properties,but also provide a new way to further explore the electron energy dissipation pathway during friction.

Classical spin liquid state in a rhombic lattice metal-organic framework

Discovering more and new geometrically frustrated systems remains an active point of inquiry in fundamental physics for the existence of unusual states of matter.Here,we report spin-liquid-like behavior in a two-dimensional(2D)rhombic lattice Fe-metal-organic framework(Fe-MOF)with frustrated antiferromagnetism.This Fe-MOF exhibits a high frustration factor f=|θCW|/TN≥315,and its long-range magnetic order is suppressed down to 180 mK.Detailed theoretical calculations demonstrate strong antiferromagnetic coupling between adjacent Fe3+ions,indicating the potential of a classical spin-liquid-like behavior.Notably,a T-linear heat capacity parameter,γ,originating from electronic contributions and with magnetic field independence up to 8 T,can be observed in the specific heat capacity measurements at low-temperature,providing further proof for the spin-liquid-like behavior.This work highlights the potential of MOF materials in geometrically frustrated systems,and will promote the research of exotic quantum physics phenomena.

由5-取代基间苯二甲酸和二咪唑衍生物构筑的两个二维钴(Ⅱ)的配合物的合成、结构及性质

通过溶剂热法合成了2个二维钴配位聚合物[Co_2(1,4-bib)_2(5-hipa)_2]_n(1)(5-H_2hipa=5-hydroxyisophthalic acid,1,4-bib=1,4-bis(1-imidazolyl)benzene),[Co(Hbpt)(4,4′-bidpe)]_n(2)(H_3bpt=biphenyl-4,4′,5-tricarboxylic acid,4,4′-bidpe=4,4′-bis(imidazol-1-yl)diphenyl ether)。X射线单晶衍射实验测定和结构解析结果表明,配合物1、2中5-hipa^(2-)、Hbpt^(2-)配体的2个相间羧基将相邻的Co^(2+)连接形成含有Co_2O_4C_2八元环和Co_2O_4C_(10)十六元环的一维链状结构。一维链之间通过1,4-bib,4,4′-bidpe配体上的咪唑基N原子与相邻Co(Ⅱ)离子配位连结形成二维层状结构。配合物1层与层之间通过相邻层中的5-hipa^(2-)配体的羟基与羧基的分子间氢键连结形成三维超分子网络结构。配合物2中,Hbpt配体的羧基氢与层内的相邻链上参与弱配位羧基氧形成层内氢键。电化学性能测试结果表明,配合物1对氧还原反应具有电催化活性。

基于二维框架的Inventor三维参数化设计

应用三维Autodesk Inventor软件,以钻机底架中拉杆旋转轴组件和立柱旋转轴组件为例,介绍了零部件的造型建模过程、二维框架的建立方法、Excel数据关联及二维框架中参数的传递,通过修改Excel表格数据,能派生出多个不同规格的同形零部件。利用Autodesk Inventor强大的参数化功能的三维设计,不仅能提高设计效率,而且能缩短设计周期,降低开发成本。

4,4'-(苯并噻唑-4,7-二取代)-二苯甲酸钴(Ⅱ)配位聚合物的溶剂热合成及结构表征

设计合成出一种线性二羧酸配体H_2btdb,利用该配体与Co轮桨型次级建筑基块通过溶剂热法构筑出一种2D+2D→3D的多孔金属有机骨架Co(btdb)(DMA)·H_2O(1),并对其进行了X射线单晶衍射、X射线粉末衍射和热重分析等表征。

基于达索平台的BIM协同设计在水处理工程中的应用

BIM技术的应用未来将会成为计算机辅助设计发展的重要趋势和方向,而其中核心的技术就是协同设计。本文简述基于达索平台三维协同设计、二维图纸及可视化应用技术的成功应用,并且介绍了基于骨架和文档模板的水厂构件建模方法。以上技术的实现能够良好地契合实际的工程设计习惯,可以在水处理行业广泛应用与推广。

安徽师范大学三维虚拟校园系统建设研究

随着虚拟现实和三维地理信息系统技术的日趋成熟,三维虚拟校园建设已成为数字校园建设的新热点.本文结合安徽师范大学三维虚拟校园建设的实际需求,分析了三维虚拟校园建设的主要内容和系统实现的总体框架,探讨了数据源的获取和处理、建模软件的选取和应用、三维模型的建立和优化等校园三维建模的技术细节,并研究了模型的快速加载与实时漫游、二三维动态交互、基于插件技术的集成应用框架等系统实现的关键技术.根据本文提出的建设方案和技术方法,采用3DMAX建模软件制作了安徽师范大学三维校园模型,并在VisualStudio 2008平台下,基于OpenGL和.NET类库,采用插件式技术编程实现了安徽师范大学三维虚拟校园原型系统,系统在运行效率、独立性、真实感和可扩展性等方面取得了较好的效果.