Metal-Organic Framework Materials for Electrochemical Supercapacitors

Exploring new materials with high stability and capacity is full of challenges in sustainable energy conversion and storage systems.Metal-organic frameworks(MOFs),as a new type of porous material,show the advantages of large specific surface area,high porosity,low density,and adjustable pore size,exhibiting a broad application prospect in the field of electrocatalytic reactions,batteries,particularly in the field of supercapacitors.This comprehensive review outlines the recent progress in synthetic methods and electrochemical performances of MOF materials,as well as their applications in supercapacitors.Additionally,the superiorities of MOFs-related materials are highlighted,while major challenges or opportunities for future research on them for electrochemical supercapacitors have been discussed and displayed,along with extensive experimental experiences.

Microporous metal-organic framework materials for efficient capture and separation of greenhouse gases

The release of anthropogenic greenhouse gases into the atmosphere poses serious risks to the environment and human health,and is a global threat of growing concern.In order to ameliorate the greenhouse gas emission problems,the efficient capture and separation of these greenhouse gases are greatly meaningful.Metal-organic framework(MOF)materials,a relatively new kind of organic-inorganic hybrid porous materials with unique framework features,tunable pore environment and high surface areas,have been widely studied as regards their applicability to this implementation.And the well-defined structures of MOF materials greatly promote the understanding of structure-property relationships.In this review,we intend to provide a profound account of significant progress in the field of capture and separation of greenhouse gases using MOFs as adsorbents,including carbon dioxide,methane,nitrous oxide and fluorocompounds(such as perfluorocarbons,sulfur hexafluoride,hydrochlorocarbons,and hydrofluocarbons).The strategies used to realize the efficient capture and separation of greenhouse gases have been summarized,and the relationships between the frameworks,their capture and separation performances and mechanisms are discussed.Furthermore,the existing challenges and perspectives with regard to the development of MOF materials for the capture and separation of greenhouse gases and industrial practical application are outlined to further promote this very significant and active emerging topic.

Metal-organic framework-based materials as key components in electrocatalytic oxidation and reduction reactions

Studies have extensively addressed the development of electrocatalytic technologies for energy storage and conversion,fuel production,and environmental protection.Electrode processes such as different oxidation and reduction reactions play a vital and significant role in these technologies.In this regard,efficient,inexpensive,and stable electrocatalysts capable can significantly promote electrochemical reactions.Unique features of metal–organic frameworks(MOFs)such as their high porosity,tunable structure,size,and pore shape,high surface area,and redox properties have introduced them as an ideal electrocatalyst candidate.This review is thus aimed at elucidating the role of MOF-based materials(pristine,derivatives and composites)as efficient electrocatalysts in energy and sensing-related oxidation and reduction reactions such as oxygen reduction reaction(ORR),hydrogen oxidation reaction(HOR),carbon dioxide reduction reaction(CO_(2)RR),urea oxidation reaction(UOR),alcohol oxidation reaction(AOR),nitrogen reduction reaction(NRR),and glucose oxidation reaction(GOR)in advanced energy and sensing devices.Also,the structure–property relationship of the electrocatalyst was elaborated for each electrocatalytic reaction.Finally,perspectives on the potential research topics for practical use of MOF-based electrocatalysts are addressed.The present review can improve the interest in MOF-based electrocatalysts to study different oxidation and reduction reactions in energy and sensing systems.

Trimetallic Metal-Organic Framework Nanoframe Superstructures: A Stress-Buffering Architecture Engineering of Anode Material toward Boosted Lithium Storage Performance

Metal-organic frameworks(MOFs)can serve as prevailing anodes for lithium-ion batteries,due to their multiple redox-active sites and prominent structural compatibility.However,the poor electronic conductivity and inferior cyclability hinder their further implementation.Herein,a synthetic methodology for trimetallic Fe-Co-Ni MOFs with nanoframe superstructures architecture(Fe-Co-Ni NFSs)via structural evolution is proposed for versatile anode materials for lithium storage.Ascribed to optimal compositional and structural optimization,the Fe-Co-Ni NFSs achieve exceptional electrochemical performance with superior specific capacity(1030 mAh g^(−1) at 0.1 A g^(−1)),outstanding rate capacity(414 mAh g^(−1) at 2 A g^(−1)),and prolonged cyclability(489 mAh g^(−1) upon 1000 cycles at 1 A g^(−1)).Both experimental and theoretical investigations reveal that the multi-component metal centers could boost electronic conductivity,confer multiple active sites,and energetically favor Li adsorption capability.Additionally,the nanoframe superstructures of Fe-Co-Ni NFSs could facilitate stress-buffering effect on volumetric expansion and prevent electrode pulverization,further improving the lithium storage capability.This work envisions a meticulous protocol for high-performance MOF anode materials for lithium-ion batteries.

Metal-organic frameworks and their composites for advanced lithium-ion batteries:Synthesis,progress and prospects

Metal-organic frameworks(MOFs)are among the most promising materials for lithium-ion batteries(LIBs)owing to their high surface area,periodic porosity,adjustable pore size,and controllable chemical composition.For instance,their unique porous structures promote electrolyte penetration,ions transport,and make them ideal for battery separators.Regulating the chemical composition of MOF can introduce more active sites for electrochemical reactions.Therefore,MOFs and their related composites have been extensively and thoroughly explored for LIBs.However,the reported reviews solely include the applications of MOFs in the electrode materials of LIBs and rarely involve other aspects.A systematic review of the application of MOFs in LIBs is essential for understanding the mechanism of MOFs and better designing related MOFs battery materials.This review systematically evaluates the latest developments in pristine MOFs and MOF composites for LIB applications,including MOFs as the main materials(anode,cathode,separators,and electrolytes)to auxiliary materials(coating layers and additives for electrodes).Furthermore,the synthesis,modification methods,challenges,and prospects for the application of MOFs in LIBs are discussed.

Synergistic catalysis of the N-hydroxyphthalimide on flower-like bimetallic metal-organic frameworks for boosting oxidative desulfurization

Synergic catalytic effect between active sites and supports greatly determines the catalytic activity for the aerobic oxidative desulfurization of fuel oils.In this work,Ni-doped Co-based bimetallic metal-organic framework(CoNi-MOF)is fabricated to disperse N-hydroxyphthalimide(NHPI),in which the whole catalyst provides plentiful synergic catalytic effect to improve the performance of oxidative desulfurization(ODS).As a bimetallic MOF,the second metal Ni doping results in the flower-like morphology and the modification of electronic properties,which ensure the exposure of NHPI and strengthen the synergistic effect of the overall catalyst.Compared with the monometallic Co-MOF and naked NHPI,the NHPI@CoNi-MOF triggers the efficient activation of molecular oxygen and improves the ODS performance without an initiator.The sulfur removal of dibenzothiophene-based model oil reaches 96.4%over the NHPI@CoNi-MOF catalyst in 8 h of reaction.Furthermore,the catalytic product of this aerobic ODS reaction is sulfone,which is adsorbed on the catalyst surface due to the difference in polarity.This work provides new insight and strategy for the design of a strong synergic catalytic effect between NHPI and bimetallic supports toward high-activity aerobic ODS materials.

Photophysics of metal-organic frameworks:A brief overview

Metal-organic frameworks(MOFs),which are self-assembled porous coordination materials,have garnered considerable attention in the fields of optoelectronics,photovoltaic,photochemistry,and photocatalysis due to their diverse structures and excellent tunability.However,the performance of MOF-based optoelectronic applications currently falls short of the industry benchmark.To enhance the performance of MOF materials,it is imperative to undertake comprehensive investigations aimed at gaining a deeper understanding of photophysics and sequentially optimizing properties related to photocarrier transport,recombination,interaction,and transfer.By utilizing femtosecond laser pulses to excite MOFs,time-resolved optical spectroscopy offers a means to observe and characterize these ultrafast microscopic processes.This approach adds the time coordinate as a novel dimension for comprehending the interaction between light and MOFs.Accordingly,this review provides a comprehensive overview of the recent advancements in the photophysics of MOFs and additionally outlines potential avenues for exploring the time domain in the investigation of MOFs.

Regulating interfacial behavior of zinc metal anode via metal-organic framework functionalized separator

Aqueous zinc ion batteries(AZIBs)are one of the promising energy storage devices.However,uncontrolled dendrite and side reactions have seriously hindered its further application.In this study,the metal-organic framework(MOF)functionalized glass fiber separator(GF-PFC-31)was used to regulate interfacial behavior of zinc metal anode,enabling the development of high-performance AZIBs.In PFC-31,there areπ-πinteractions between two adjacent benzene rings with a spacing of 3.199 A.This spacing can block the passage of[Zn(H_(2)O)_6]^(2+)(8.6 A in diameter)through the GF-PFC-31 separator to a certain extent,which promotes the deposition process of Zn ions.In addition,the sulfonic acid group(-S03H)contained in GF-PFC-31 can form a hydrogen bonding network with H_(2)O,which can provide a desolvation effect and reduce the side reaction.Consequently,GF-PFC-31 separator achieves uniform deposition of Zn ions.The Zn‖GF-PFC-31‖Zn symmetric cell exhibits stable cycle life(3000 h at 1.2 mA cm^(-2),2000 h at 0.3 mA cm^(-2),and 2000 h at 5.0 mA cm^(-2)),and Zn‖GF-PFC-31‖MnO_(2) full cell with GF-PFC-31 separator can cycle for 1000 cycles at 1.2 A g^(-1)with capacity retention rate of 82.5%.This work provides a promising method to achieve high-performance AZIBs.

Porous framework materials for energy&environment relevant applications:A systematic review

Carbon peaking and carbon neutralization trigger a technical revolution in energy&environment related fields.Development of new technologies for green energy production and storage,industrial energy saving and efficiency reinforcement,carbon capture,and pollutant gas treatment is in highly imperious demand.The emerging porous framework materials such as metal–organic frameworks(MOFs),covalent organic frameworks(COFs)and hydrogen-bonded organic frameworks(HOFs),owing to the permanent porosity,tremendous specific surface area,designable structure and customizable functionality,have shown great potential in major energy-consuming industrial processes,including sustainable energy gas catalytic conversion,energy-efficient industrial gas separation and storage.Herein,this manuscript presents a systematic review of porous framework materials for global and comprehensive energy&environment related applications,from a macroscopic and application perspective.

Rational design of a novel two-dimensional porous metal-organic framework material for efficient benzene sensor

As a common volatile organic compound,benzene(C_(6)H_(6)) exists in home decoration pollution gas widely,which causes great harm to the environment and human health.Therefore,it is necessary to rationally design advanced materials with high selectivity to detect and capture C_(6)H_(6).Herein,combined with the d-band center theory and cohesive energy,a new two-dimensional metal-organic framework material,Ni-doped hexaaminobenzene-based coordination polymer(Ni-HAB-CP)is designed,and its application potential as a C_(6)H_(6) sensor are systematically investigated by using first principles calculation.The result shows that Ni-HAB-CP has a strong adsorption for C_(6)H_(6) without any additional method.In addition,NiHAB-CP can maintain good conductivity before and after adsorption,and C_(6)H_(6) can be easily desorbed from the surface of Ni-HAB-CP by charge control.Moreover,the I-V curve calculated by Atomistix Toolkit(ATK)reveals that Ni-HAB-CP has high sensitivity and selectivity to C_(6)H_(6).Hence,Ni-HAB-CP is expected to be used as a potential material for a highly efficient and recyclable C_(6)H_(6) sensor in the future.The calculation and analysis methods used in this paper could provide a certain theoretical basis and reference for the future research of gas sensors.

A Review on Metal-Organic Framework-Derived Porous Carbon-Based Novel Microwave Absorption Materials

The development of microwave absorption materials(MAMs) is a considerable important topic because our living space is crowed with electromagnetic wave which threatens human’s health.And MAMs are also used in radar stealth for protecting the weapons from being detected.Many nanomaterials were studied as MAMs,but not all of them have the satisfactory performance.Recently,metal-organic frameworks(MOFs) have attracted tremendous attention owing to their tunable chemical structures,diverse properties,large specific surface area and uniform pore distribution.MOF can transform to porous carbon(PC) which is decorated with metal species at appropriate pyrolysis temperature.However,the loss mechanism of pure MOF-derived PC is often relatively simple.In order to further improve the MA performance,the MOFs coupled with other loss materials are a widely studied method.In this review,we summarize the theories of MA,the progress of different MOF-derived PC-based MAMs,tunable chemical structures incorporated with dielectric loss or magnetic loss materials.The different MA performance and mechanisms are discussed in detail.Finally,the shortcomings,challenges and perspectives of MOF-derived PC-based MAMs are also presented.We hope this review could provide a new insight to design and fabricate MOF-derived PC-based MAMs with better fundamental understanding and practical application.

State of the Art and Prospects in Metal-Organic Framework-Derived Microwave Absorption Materials

Microwave has been widely used in many fields,including communication,medical treatment and military industry;however,the corresponding generated radiations have been novel hazardous sources of pollution threating human’s daily life.Therefore,designing high-performance microwave absorption materials(MAMs)has become an indispensable requirement.Recently,metal-organic frameworks(MOFs)have been considered as one of the most ideal precursor candidates of MAMs because of their tunable structure,high porosity and large specific surface area.Usually,MOF-derived MAMs exhibit excellent electrical conductivity,good magnetism and sufficient defects and interfaces,providing obvious merits in both impedance matching and microwave loss.In this review,the recent research progresses on MOF-derived MAMs were profoundly reviewed,including the categories of MOFs and MOF composites precursors,design principles,preparation methods and the relationship between mechanisms of microwave absorption and microstructures of MAMs.Finally,the current challenges and prospects for future opportunities of MOF-derived MAMs are also discussed.

A composite metal-organic framework material with high selective adsorption for dibenzothiophene

A copper-centred metal-organic framework material MOF-101 with 2-bromine terephthalic acid as ligands was synthesized by solvothermal method at 70 ℃ and modified by loading Ag^+to improve the selective adsorption performance.The MOF-101 and Ag^+/MOF-101 prepared were characterised by powder X-ray diffraction,X-ray fluo re scence,Fourier trans fo rm infrared spectroscopy,scanning electro n microscopy,and thermogravimetric analysis.The adsorptive desulphurisation was quantified by adsorbing dibenzothiophene(DBT)from model oils.The loading of Ag^+enhanced the deep adsorptive desulfurization capacity fo r DBT and significantly weaken the adsorption competitiveness of toluene.As a result,the DBT concentration of model oil was reduced from 50 ppms to 10.2 ppms.Possible understandings were put forward to explain the adsorption performance of Ag^+/MOF-101.The kinetics and isotherm data can be well-described by the pseudo-second-order kinetic model and the Langmuir model.

Metal-organic framework-derived phosphide nanomaterials for electrochemical applications

Because of features,such as adjustable structures,high porosity,and high crystallinity,metal-organic frameworks(MOFs)deservedly have received considerable attention.Nevertheless,there is still room for improvements in the electrical conductivity and chemical stability of some MOFs,because of which they cannot be utilized as electrode materials.Fortunately,MOF derivatives have received widespread attention in recent years,especially phosphide materials,which are widely used in practical applications because of their outstanding conductivity,excellent specific surface area,and standout charge mobility.In this review,the latest developments of MOF-derived phosphides in electrocatalysis related to energy,including the excellent performance in terms of electrochemical energy storage and ingenious strategies,and diversified synthetic approaches are emphasized and summarized.Additionally,the arduous task and feasible proposals of MOF-derived phosphides are also discussed.

Metal-Organic Framework-Based Sulfur-Loaded Materials

Lithium-sulfur batteries(LSBs)are considered promising new energy storage systems given their outstanding theoretical energy densities.Nevertheless,issues such as low electrical conductivity and severe volume expansion,along with the formation of polysulfides during cycling,restrict their practical applications.To overcome these issues,it is necessary to find suitable and effective sulfur host materials.Metal-organic frameworks(MOFs),which are porous crystalline materials in the bourgeoning developmental stages,have demonstrated enormous potential in LSBs owing to their high porosity and tunable porous structure.Herein,we provide a comprehensive overview of MOF-based sulfur-loaded materials and discuss the charge/discharge mechanisms,strategies of enhancing battery performance,sulfur loading methods,and applications in LSBs.An outlook on future directions,prospects,and possible obstacles for the development of these materials is also provided.

Mn-Based Two Dimensional Metal-Organic Framework Material from Benzimidazole-5,6-dicarboxylic Acid

A new two-dimensional metal-organic framework （MOF） structure has been synthesized by mild solvothermal reaction of MnC12o4H20 with 1H-benzimidazole-5,6-dicarboxylic acid （H3bidc） at 85℃. The structure has been characterized by single-crystal X-ray diffraction, powder X-ray diffraction （PXRD）, infrared spectroscopy （FT-IR）, and thermogravimetric analysis （TGA）. Single-crystal X-ray diffraction analysis revealed that this MOF is a five-coordinated Mn（II） compound exhibiting a layered 2D network, in which the hydrogen-bonding interactions between uncoordinated carboxylic oxygen atoms and N--H groups in the imidazole rings play a key role in the fi- nal 3D supramolecular architecture. This MOF shows high thermal stability up to 400℃. Furthermore, XRD pattern of the MOF structure was retained for up to 20 d after soaked in water, and only 2.8 wt% of the MOF was decomposed within the first 48 h in water.

Equilibrium,Kinetics and Thermodynamics of the Adsorption of Methylene Blue onto a Metal-Organic Frameworks Material,Copper Coordination Polymer with Dithiooxamide

The equilibrium, kinetics and thermodynamics of the adsorption of methylene blue( MB) from aqueous solution onto copper coordination polymer with dithiooxamide( H2dtoaCu),one of the metal-organic frameworks( MOFs),were investigated in a batch adsorption system as a function of initial pH, adsorbent concentration, contact time, initial dye concentration, and temperature. The Langmuir, Freundlich, and DubininRadushkevich( D-R) isotherm models were used for modeling the adsorption equilibrium. It was found that Langmuir model yielded a much better fit than the Freundlich model under different temperatures. The maximum monolayer adsorption capacities of MB were 192. 98,229. 86,and 297. 38 mg /g at 298,308,and 318 K,respectively. The calculated mean adsorption energy( 8. 26-11. 04 kJ /mol) using D-R model indicated that the adsorption process might take place by chemical adsorption mechanism.Otherwise,the kinetic studies revealed that the adsorption process could be well explained by pseudo-second-order rate kinetics and intraparticle diffusion was not the rate-limiting step.Thermodynamic studies indicated that this system was feasible,spontaneous,and endothermic process. Based on these studies,H2dtoaCu can be considered as a potential adsorbent for the removal of MB from aqueous solution.

Metal-Organic Framework-Based Solid Acid Materials for Biomass Upgrade

Biomass is a green and producible source of energy and chemicals.Hence,developing high-efficiency catalysts for biomass utilization and transformation is urgently demanded.Metal-organic framework(MOF)-based solid acid materials have been considered as promising catalysts in biomass transformation.In this review,we first introduce the genre of Lewis acid and Brønsted acid sites commonly generated in MOFs or MOF-based composites.Then,the methods for the generation and adjustment of corresponding acid sites are overviewed.Next,the catalytic applications of MOF-based solid acid materials in various biomass transformation reactions are summarized and discussed.Furthermore,based on our personal insights,the challenges and outlook on the future development of MOF-based solid acid catalysts are provided.We hope that this review will provide an instructive roadmap for future research on MOFs and MOF-based composites for biomass transformation.

UiO-66 type metal-organic framework as a multifunctional additive to enhance the interfacial stability of Ni-rich layered cathode material

To effectively alleviate the surface structure degradation caused by electrolyte corrosion and transition metal(TM) dissolution for Ni-rich(Ni content > 0.6) cathode materials, porous Zirconium based metalorganic frameworks(Zr-MOFs, UiO-66) material is utilized herein as a positive electrode additive. UiO-66 owns tunable attachment sites and strong binding affinity, making itself an efficient defluorination agent to suppress the undesirable reactions caused by fluorine species. Besides, it can also relieve TMs dissolution and block the migration of TMs toward anode side since it’s a multifarious metal ions adsorbent,realizing both cathode and anode interface protection. Benefiting from these advantages, the UiO-66 assistant Ni-rich cathode achieves superior cycling stability. Particularly in full cell, the positive effects of this multifunctional additive are more pronounced than in the half-cell, that is after 400 cycles at 2 C,the capacity retention has doubled with the addition of UiO-66. More broadly, this unique application of functional additive provides new insight into the degradation mechanism of layered cathode materials and offers a new avenue to develop high-energy density batteries.

Integrating Levels of Hierarchical Organization in Porous Organic Molecular Materials

Porous organic molecular materials(POMMs)are an emergent class of molecular-based materials characterized by the formation of extended porous frameworks,mainly held by non-covalent interactions.POMMs represent a variety of chemical families,such as hydrogen-bonded organic frameworks,porous organic salts,porous organic cages,C-H···πmicroporous crystals,supramolecular organic frameworks,π-organic frameworks,halogen-bonded organic framework,and intrinsically porous molecular materials.In some porous materials such as zeolites and metal organic frameworks,the integration of multiscale has been adopted to build materials with multifunctionality and optimized properties.Therefore,considering the significant role of hierarchy in porous materials and the growing importance of POMMs in the realm of synthetic porous materials,we consider it appropriate to dedicate for the first time a critical review covering both topics.Herein,we will provide a summary of literature examples showcasing hierarchical POMMs,with a focus on their main synthetic approaches,applications,and the advantages brought forth by introducing hierarchy.