Recent Progress in Synthesis, Mechanism and Applications of Zinc-Based Metal-Organic Frameworks for Fluorescent Sensing

As more and more pollutants threaten human health, it is necessary and essential to develop sensitive, accurate and rapid methods and sensory materials to detect harmful substance. Metal-organic frameworks (MOFs) are inorganic-organic hybrids assembled from inorganic metal ions or clusters and suitable organic ligands. Zinc-based MOFs (Zn-MOFs) have emerged as one of the most promising sensory material of MOFs for practical applications, and attracted significant attention due to structural diversity and incomparable stability properties. However, there are few reviews on systemic summary of synthesis design, mechanism and application of Zn-MOFs. In this review, we summarize the synthesis design methods, structure types and luminescence mechanism of Zn-MOFs sensor recognition in the past ten years and their applications in metal cations, anions, organic compounds and other analytes. Finally, we present a short conclusion, and look forward to the future development direction of Zn-MOFs.

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.

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.

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.

Adsorption of Sulfamethoxazole on Nanoporous Carbon Derived from Metal-Organic Frameworks

Nanoporous Carbon (NPC) with high surface area of 1379 M2/G and high proportion of micropore and mesopore volume of 2.90 Cm3/G was prepared by carbonization of metal?organic frameworks ZIF-8. The adsorption of NPC towards the representative sulfonamide antibiotics sulfamethoxazole (SMX) from aqueous solutions was explored, in comparison with powder active carbon (AC). The adsorption kinetics and isotherms showed that the maximum adsorption capacity (Qm) of NPC toward SMX was 757 Mg/G, around 2 times than that of AC adsorption. The high adsorption affinity of NPC was related to the high surface area and special Mic/Mesopore structure. The pore-filling mechanism as well as electrostatic interaction had important influence on the high adsorption of NPC. The results implied that nanoporous carbon derived from mofs could remove the contaminants from aqueous solutions effectively, and would be a promising adsorbent for the removal of contaminants in the future.

A review on anode materials for lithium/sodium-ion batteries

Since lithium-ion batteries(LIBs) have been substantially researched in recent years, they now possess exceptional energy and power densities, making them the most suited energy storage technology for use in developed and developing industries like stationary storage and electric cars, etc. Concerns about the cost and availability of lithium have prompted research into alternatives, such as sodium-ion batteries(SIBs), which use sodium instead of lithium as the charge carrier. This is especially relevant for stationary applications, where the size and weight of battery are less important. The working efficiency and capacity of these batteries are mainly dependent on the anode, cathode, and electrolyte. The anode,which is one of these components, is by far the most important part of the rechargeable battery.Because of its characteristics and its structure, the anode has a tremendous impact on the overall performance of the battery as a whole. Keeping the above in view, in this review we critically reviewed the different types of anodes and their performances studied to date in LIBs and SIBs. The review article is divided into three main sections, namely:(i) intercalation reaction-based anode materials;(ii) alloying reaction-based anode materials;and(iii) conversion reaction-based anode materials, which are further classified into a number of subsections based on the type of material used. In each main section, we have discussed the merits and challenges faced by their particular system. Afterward, a brief summary of the review has been discussed. Finally, the road ahead for better application of Li/Na-ion batteries is discussed, which seems to mainly depend on exploring the innovative materials as anode and on the inoperando characterization of the existing materials for making them more capable in terms of application in rechargeable batteries.

Double spatial confinement on ruthenium nanoparticles inside carbon frameworks as durable catalysts for a quasi-solid-state Li–O_(2) battery

The rational design of large-area exposure,nonagglomeration,and longrange dispersion of metal nanoparticles(NPs)in the catalysts is critical for the development of energy storage and conversion systems.Little attention has been focused on modulating and developing catalyst interface contact engineering between a carbon substrate and dispersed metal.Here,a highly dispersed ultrafine ruthenium(Ru)NP strategy by double spatial confinement is proposed,that is,incorporating directed growth of metal–organic framework crystals into a bacterial cellulose templating substrate to integrate their respective merits as an excellent electrocatalytic cathode catalyst for a quasi-solid-state Li–O_(2) battery.The porous carbon matrix with highly dispersed ultrafine Ru NPs is well designed and used as cathode catalysts in a Li–O_(2) battery,demonstrating a high discharge areal capacity of 6.82 mAh cm^(–2) at 0.02 mA cm^(–2),a high-rate capability of 4.93 mAh cm^(–2) at 0.2 mA cm^(–2),and stable discharge/charge cycling for up to 500 cycles(2000 h)with low overpotentials of~1.4 V.This fundamental understanding of the structure–performance relationship demonstrates a new and promising approach to optimize highly efficient cathode catalysts for solid-state Li–O_(2) batteries.

Conducting polymer-functionalized mesoporous metal-organic frameworks for high-performance Li-S battery

It was known that mesoporous metal-organic frameworks(MOFs)with hierarchical pores and unsaturated metal sites can effectively inhibit the shuttle effect of lithium polysulfides in lithium-sulfur battery,however,the unsatisfactory structural stability and electrical conductivity limit the application of mesoporous MOFs(MMOFs)in Li-S batteries.Aiming at sensible solutions,the conductive polyaniline(PANI)was incorporated into the MMOF to enhance the discharge capacity and the cycling stability of proposed Li-S batteries,as the stability and the conductivity of the MMOF cathode was improved simultaneously.The activated MMOF-PANI provides physical and chemical adsorption of polysulfides against their shuttle effect.Moreover,the introduction of PANI into the channels of MMOF effectively improves the conductivity of MMOF,thus improving the electrochemical performance of the MMOF-PANI-based batteries.Benefiting from these synergetic effects,the S@MMOF-PANI cathode delivers improved electrochemical performance including excellent rate performance and cycling stability.The battery shows an initial capacity of 777.7 mAh·g^(−1)at 2.0 C and a low decay rate of 0.06%per cycle in 1,000 cycles and approximately a repeatable rate performance.

Synthesis of Cu-Doped Layered Transition Metal Oxide Cathode Materials Directly from Metal-Organic Frameworks for Sodium-Ion Batteries

Mn-based layered transition metal oxides are promising cathode materials for sodium-ion batteries(SIBs)because of their high theoretical capacities,abundant raw materials,and environment-friendly advantages.However,they often show insufficient performance due to intrinsic issues including poor structural stability and dissolution of Mn^(3+).Atomic doping is an effective way to address these structural degradation issues.Herein,we reported a new synthesis strategy of a Cu-doped layered cathode by directly calcinating a pure metal-organic framework.Benefiting from the unique structure of MOF with atomic-level Cu doping,a homogeneous Cu-doped layered compound P2-Na_(0.674)Cu_(0.01)Mn_(0.99)O_(2) was obtained.The Cu substitution promotes the crystal structural stability and suppresses the dissolution of Mn,thus preventing the structure degradation of the layered cathode materials.A remarkably enhanced cyclability is realized for the Cu-doped cathode compared with that without Cu doping,with 83.8%capacity retention after 300 cycles at 100 mA·g^(-1).Our findings provide new insights into the design of atomic-level doping layered cathode materials constructed by MOFs for high-performance SIBs.

Tightened1D/3Dcarbonheterostructure infiltratingphase change materials for solar-thermoelectric energy harvesting:Faster and better

Extensive use of thermal energy in daily life is ideal for reducing carbon emissions to achieve carbon neutrality;however,the effective collection of thermal energy is a major hurdle.Thermoelectric(TE)conversion technology based on the Seebeck effect and thermal energy storage technology based on phase change materials(PCMs)represent smart,feasible,and research-worthy approaches to overcome this hurdle.However,the integration of multiple thermal energy sources freely existing in the environment for storage and output of thermal and electrical energy simultaneously still remains a huge challenge.Herein,three-dimensional(3D)nanostructured metal-organic frameworks(MOFs)are in situ nucleated and grown onto carbon nanotubes(CNTs)via coordination bonding.After calcination,the prepared core-shell structural CNTs@MOFs are transformed into tightened 1D/3D carbon heterostructure loading Co nanoparticles for efficient solar-thermoelectric energy harvesting.Surprisingly,the corresponding composite PCMs show a record-breaking solar-thermal conversion efficiency of 98.1%due to the tightened carbon heterostructure and the local surface plasmon resonance effect of Co nanoparticles.Moreover,our designed all-in-one composite PCMs are also capable of creating an electrical potential of 0.5 mV based on the Seebeck effect without a TE generator.This promising approach can store thermal and electrical energy simultaneously,providing a new direction in the design of advanced all-in-one multifunctional PCMs for thermal energy storage and utilization.

Amorphous nickel-cobalt bimetal-organic framework nanosheets with crystalline motifs enable efficient oxygen evolution reaction: Ligands hybridization engineering

Development of high-efficiency and low-cost electrocatalyst for oxygen evolution reaction(OER) is very important for use at alkaline water electrolysis.Metal-organic frameworks(MOF) provide a rich platform for designing multi-functional materials due to their controllable composition and ultra-high surface area.Herein,we report our findings in the development of amorphous nickel-cobalt bimetal-organic framework nanosheets with crystalline motifs via a simple "ligands hybridization engineering" strategy.These complexes' ligands contain inorganic ligands(H_2 O and NO_3) and organic ones,hexamethylenetetramine(HMT).Further,we investigated a series of mixed-metal with multi-ligands materials as OER catalysts to explore their possible advantages and features.It is found that the Ni doping is an effective approach for optimizing the electronic configuration,changing lattice ordering degree,and thus enhancing activities of HMT-based electrocatalysts.Also,the crystalline-amorphous boundaries of various HMTbased electrocatalyst can be easily controlled by simply changing amounts of Ni-precursor added.As a result,the optimized ultrathin(Co,0.3 Ni)-HMT nanosheets can reach a current density of 10 mA cm^(-2)at low overpotential of 330 mV with a small Tafel slope of 66 mV dec^(-1).Our findings show that the electronic structure changes induced by Ni doping,2 D nanosheet structure,and MOF frameworks with multiligands compositions play critical roles in the enhancement of the kinetically sluggish electrocatalytic OER.The present study emphasizes the importance of ligands and active metals via hybridization for exploring novel efficient electrocatalysts.

Room-temperature ferrimagnetism and size-modulated electronic structures in two-dimensional cluster-based metal-organic frameworks

Cluster-assembled materials have attracted particular attention for their complex hierarchical structures and unique properties.However,the majority of cluster-based assemblies developed so far are either non-magnetic or only exhibit magnetic ordering with a relatively low Curie temperature,limiting their applications in spintronics.Thus,two-dimensional(2D)cluster-assembled materials with room-temperature magnetism remain highly desirable.For this purpose,based on first principles calculations,we design a series of thermodynamically stable 2D cluster-based metal-organic frameworks(MOFs)Fe_(n)-(pyz)(n=1-6)by utilizing Fenmetal clusters as nodes and nitrogen-containing pyrazine ligands as organic linkers.These 2D cluster-based MOFs exhibit robust ferrimagnetic ordering due to the strong d-p direct exchange interaction between d-electron spin of Fe_(n)(n=1-6)clusters and charge transfer-induced p-electron spin of pyrazine ligands.In particular,the ferrimagnetic Curie temperatures are well above room temperature(up to 836 K).Additionally,altering the size of Fe_(n)clusters in Fe_(n)-(pyz)(n=1-6)MOFs results in diverse functional spintronic properties,including bipolar magnetic semiconductors,half semiconductors and Dirac half metals.Moreover,these 2D assembled MOFs possess sizable magnetic anisotropy energies,up to 9.16 me V per formula.

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.

Diagnosis and subtype classification on serum peptide fingerprints by mesoporous polydopamine with built-in metal-organic framework

Crohn's disease(CD)as a big issue to public health needs an accurate diagnosis urgently that is the common challenge among internal diseases.Herein,we design a mesoporous polydopamine with builtin metal-organic frameworks(dubbed MMP-b-MOFs)to combine with high-throughput mass spectrometry to extract serum peptide fingerprints from CD and healthy controls(HC).Benefitting by the sizeexclusion and strong hydrophilicity of MMP-b-MOFs,the extracted peptide fingerprints present extremely high quality.CD and HC are explicitly discriminated with orthogonal partial least squares discriminant analysis(OPLS-DA),the corresponding area under the curve(AUC)value is 1.000.Moreover,eight peptides with clear identity are screened out and achieve the accurate diagnosis and subtype classification of CD,with all AUC values up to 1.000.Moreover,the unsupervised model is also established to precisely classify HC and CD based on these eight clearly identified peptides.This work brings great benefits for clinical detection especially internal medicine.

MOF‑Derived CoSe2@N‑Doped Carbon Matrix Confined in Hollow Mesoporous Carbon Nanospheres as High‑Performance Anodes for Potassium‑Ion Batteries

In this work,a novel vacuum-assisted strategy is proposed to homogenously form Metal-organic frameworks within hollow mesoporous carbon nanospheres(HMCSs)via a solid-state reaction.The method is applied to synthesize an ultrafine CoSe2 nanocrystal@N-doped carbon matrix confined within HMCSs(denoted as CoSe2@NC/HMCS)for use as advanced anodes in highperformance potassium-ion batteries(KIBs).The approach involves a solvent-free thermal treatment to form a Co-based zeolitic imidazolate framework(ZIF-67)within the HMCS templates under vacuum conditions and the subsequent selenization.Thermal treatment under vacuum facilitates the infiltration of the cobalt precursor and organic linker into the HMCS and simultaneously transforms them into stable ZIF-67 particles without any solvents.During the subsequent selenization process,the“dual confinement system”,composed of both the N-doped carbon matrix derived from the organic linker and the small-sized pores of HMCS,can effectively suppress the overgrowth of CoSe2 nanocrystals.Thus,the resulting uniquely structured composite exhibits a stable cycling performance(442 mAh g^−1 at 0.1 A g^−1 after 120 cycles)and excellent rate capability(263 mAh g^−1 at 2.0 A g^−1)as the anode material for KIBs.

High-Performance Aqueous Zinc-Ion Batteries Realized by MOF Materials

Rechargeable aqueous zinc-ion batteries(ZIB s) have been gaining increasing interest for large-scale energy storage applications due to their high safety,good rate capability,and low cost.However,the further development of ZIB s is impeded by two main challenges:Currently reported cathode materials usually suffer from rapid capacity fading or high toxicity,and meanwhile,unstable zinc stripping/plating on Zn anode seriously shortens the cycling life of ZIBs.In this paper,metal-organic framework(MOF) materials are proposed to simultaneously address these issues and realize high-performance ZIB s with Mn(BTC) MOF cathodes and ZIF-8-coated Zn(ZIF-8@Zn) anodes.Various MOF materials were synthesized,and Mn(BTC) MOF was found to exhibit the best Zn^2+-storage ability with a capacity of 112 mAh g^-1.Zn^2+ storage mechanism of the Mn(BTC) was carefully studied.Besides,ZIF-8@Zn anodes were prepared by coating ZIF-8 MOF material on Zn foils.Unique porous structure of the ZIF-8 coating guided uniform Zn stripping/plating on the surface of Zn anodes.As a result,the ZIF-8@Zn anodes exhibited stable Zn stripping/plating behaviors,with 8 times longer cycle life than bare Zn foils.Based on the above,high-performance aqueous ZIBs were constructed using the Mn(BTC) cathodes and the ZIF-8@Zn anodes,which displayed an excellent long-cycling stability without obvious capacity fading after 900 charge/discharge cycles.This work provides a new opportunity for high-performance energy storage system.

Recent progress on MOF-derived carbon materials for energy storage

Metal-organic frameworks(MOFs)are of quite a significance in the field of inorganic-organic hybrid crystals.Especially,MOFs have attracted increasing attention in recent years due to their large specific surface area,desirable electrical conductivity,controllable porosity,tunable geometric structure,and excellent thermal/chemical stability.Some recent studies have shown that carbon materials prepared by MOFs as precursors can retain the privileged structure of MOFs,such as large specific surface area and porous structure and,in contrast,realize in situ doping with heteroatoms(eg,N,S,P,and B).Moreover,by selecting appropriate MOF precursors,the composition and morphology of the carbon products can be easily adjusted.These remarkable structural advantages enable the great potential of MOF-derived carbon as high-performance energy materials,which to date have been applied in the fields of energy storage and conversion systems.In this review,we summarize the latest advances in MOF-derived carbon materials for energy storage applications.We first introduce the compositions,structures,and synthesis methods of MOF-derived carbon materials,and then discuss their applications and potentials in energy storage systems,including rechargeable lithium/sodium-ion batteries,lithium-sulfur batteries,supercapacitors,and so forth,in detail.Finally,we put forward our own perspectives on the future development of MOF-derived carbon materials.

High-sensitivity shortwave infrared photodetectors of metal-organic frameworks integrated on 2D layered materials

Photodetectors operating in the shortwave infrared region are of great significance due to their extensive applications in both commercial and military fields.Narrowbandgap two-dimensional layered materials(2DLMs)are considered as the promising candidates for constructing nextgeneration high-performance infrared photodetectors.Nevertheless,the performance of 2DLMs-based photodetectors can hardly satisfy the requirements of practical applications due to their weak optical absorption.In the present study,a strategy was proposed to design high-performance shortwave infrared photodetectors by integrating metalorganic frameworks(MOFs)nanoparticles with excellent optical absorption characteristics and 2DLM with high mobility.Further,this study demonstrated the practicability of this strategy in a MOF/2DLM(Ni-CAT-1/Bi_(2)Se_(3))hybrid heterojunction photodetector.Due to the transfer of photo-generated carriers from the MOF to Bi_(2)Se_(3),the MOF nanoparticles integrated on the Bi_(2)Se_(3) layer can increase the photocurrent by 2-3 orders of magnitude.The resulting photodetector presented a high responsivity of 4725 A W^(−1) and a superior detectivity of 3.5×10^(13) Jones at 1500 nm.The outstanding performance of the hybrid heterojunction arises from the synergistic function of the enhanced optical absorption and photogating effect.In addition,the proposed device construction strategy combining MOF photosensitive materials with 2DLMs shows a high potential for the future high-performance shortwave infrared photodetectors.

Recent advances of two-dimensional metal-organic frameworks in alkaline electrolysis water for hydrogen production

Hydrogen evolution production via electrolysis of water in alkaline solution is a promising mean of industrial hydrogen production.However,inefficiency and high cost restrict its industrialization development.Based on extensive studies of experimental and theoretical investigations,two-dimensional(2D)materials are promising substitute of noble metals for hydrogen evolution reaction(HER)with low cost and high-efficiency.Herein,recent progress in 2D metal-organic frameworks(MOFs)for HER in alkaline electrolyte is systematically discussed and summarized.This review describes the strategies about how to design and optimize the structure of 2D MOF-based materials as HER electrocatalysts with well performance and aims to provide potential avenues for industrial hydrogen production.Additionally,the challenges and future directions ahead in this field are also proposed.