Traditional Metal-organic Frameworks Research Articles

Metal-organic framework/MXene nanohybrid composites as an emerging electrochemical sensing platform for food safety and biomedical monitoring: From synthesis to application

Metal-organic frameworks (MOFs) are created through the self-assembly process of metal ions or clusters with organic linkers. These materials have attracted important interest owing to their advantageous features, comprising abundant pore structures, ultrahigh porosity, and well-exposed active sites. However, some traditional MOFs have limitations in terms of low stability and conductivity. Despite significant endeavors to enhance the stability of MOF materials, limited advancement has prompted researchers to concentrate on the development of hybrid materials. MXenes, a group of 2D transition-metal compounds comprising nitrides, carbides, and carbonitrides, are recognized for their diverse composition and their ability to form various buildings with rich surface chemistry. The hybridization of MOFs with functional MXene layered could be advantageous if the host structure offers suitable interactions to enhance and stabilize the desired features. Current research has concentrated on incorporating MXenes and MOFs to generate nanohybrid materials with boosted electrochemical features, thus broadening the scope for new applications. This review explores potential design approaches for MXene@MOF nanohybrids, the tunable characteristics of the resulting hybrids, and their use in electrochemical sensing platforms for food safety and biomedical monitoring. Finally, the authors discuss the challenges and future opportunities of MOF@MXene-derived nanocomposites.

Ligand regulation and capacitive properties of nickel based pyrazole trinuclear copper cluster organic framework

Traditional metal organic framework (MOF) hinders its application as high-performance electrode materials for supercapacitors due to the limited electron transfer efficiency and conjugation of its ligand molecules. Therefore, in this article, highly electrochemical active pyrazole trincore-copper cluster derivatives as the core unit were covalently assembled by Schiff base reaction with organic linkers of different structures to obtain a series of structurally different electroactive ligands. It was found that ligands with multiactive metal chelation site structure with polydentate carboxylate linker and aromatic extension showed high coordination ability and high degree of conjugation. The nickel-based MOF synthesized with this novel electroactive ligand exhibited a high specific capacitance of 1804 Fg−1 at a current density of 1 Ag−1. At a power density of 747.25 W kg−1, the maximum energy density of the assembled asymmetric supercapacitor assembled with Cu-PyAc-Am2Ac-Ni is 58.95 Wh kg−1 with cycling stability of 88.95 % after 5000 charges and discharges. This means that Cu-PyAc-Am2Ac-Ni is a promising electrode material for supercapacitors.

Precise selection and separation of ribavirin by nanoconfined imprinted MOFs membrane

Metal-organic frameworks (MOFs) are highly tunable materials with potential as porous media in membrane separations. However, traditional MOFs are usually not specific and selective. Here, we demonstrate a nanocomposite molecularly imprinted MOFs membrane material that can selectively adsorb and separate specific molecules. We demonstrated this adsorption-separation mechanism by introducing ribavirin molecules into multicomponent MOFs by molecular imprinting strategy and performing permeation and dynamic permeation tests. Due to the previously formed nanocages with a specific structure inside the MOFs, combined with the synergistic effect of the subsequent secondary imprinting, excellent selectivity (more than 6) and effective adsorption (46.46 mg g−1) were displayed by the obtained imprinted membrane. The stability of the membrane was measured by the process of dynamic osmosis, and the results showed that the membrane always had a large factor of separation (greater than 7). The experimental results and conclusions of this paper provide new theoretical and practical support for solving the key scientific issues of the “trade-off” effect between the permeation flux and permeation selectivity of template molecules in the traditional molecularly imprinted membranes (MIMs) osmotic separation process.

Tailoring Enantiomeric Chiral Channels in Metal-Peptide Networks: A Novel Foldamer-Based Approach for Host-Guest Interactions.

Designing chiral channels in organic frameworks presents an ongoing challenge due to the intricate control of size, shape, and functionality required. A novel approach is presented, which crafts enantiomeric chiral channels in metal-peptide networks (MPNs) by integrating short foldamer ligands with CuI clusters. The MPN structure serves as a 3D blueprint for host-guest chemistry, fostering modular substitution to refine chiral channel properties at the atomic scale. Incorporating hydrogen bond networks augments guest molecule interactions with the channel surface. This approach expedites enantiomer discrimination in racemic mixtures and incites adaptable guest molecules to take on specific axially chiral conformations. Distinct from traditional metal-organic frameworks (MOFs) and conventional reticular architectures, this foldamer-based methodology provides a predictable and customizable host-guest interaction system within a 3D topology. This innovation sets the stage for multifunctional materials that merge host-guest interaction systems with metal-complex properties, opening up potential applications in catalysis, sensing, and drug delivery.

Scalable and interfacial gap‐free mixed matrix membranes for efficient anion separation

AbstractMixed matrix membranes (MMMs) are promising in ion separation due to the simple preparation process. However, traditional metal–organic framework and covalent organic framework fillers lack the solution processibility and show interfacial defects between polymer matrixes and fillers, resulting in unsatisfactory separation performance. Herein, a soluble porous organic cage (POC) (i.e., CC3) is used as the filler to fabricate a large scale (~2000 cm2) and interfacial gap‐free ionic polymer (HPABP)‐CC3 membrane by a facile co‐solvent casting and rapid crystallization method. The resultant HPABP‐CC3(15) membrane shows a high Cl− flux of 2.24 mol m−2 h−1 and a Cl−/SO42− selectivity of 12.67, which is 3.6 and 3.0 times that of the HPABP membrane, respectively. Moreover, the HPABP‐CC3 membranes possess excellent cyclic and long‐term stability during the electrodialysis process. Therefore, we provide a facile strategy to scale up POC MMMs with synergistically enhanced ion flux and selectivity and the possibility for potential industrial ion separations.

Versatile Multi-Wavelength Light-Responsive Metal-Organic Frameworks Micromotor through Porphyrin Metalation for Water Sterilization.

Traditional metal-organic frameworks (MOFs) based micro/nanomotors (MOFtors) can achieve three-dimensional (3D) motion mainly depending on noble metal (e.g., Pt), toxic fuels (e.g., hydrogen peroxide), and surfactants, or under external magnetic fields. In this study, light-driven MOFtors are constructed based on PCN-224(H) and regulated their photothermal and photochemical properties responding to the light of different wavelengths through porphyrin metalation. The resulting PCN-224(Fe) MOFtors presented a strong 3D motion at a maximum speed of 1234.9 ± 367.5µm s-1 under visible light due to the various gradient fields by the photothermal and photochemical effects. Such MOFtors exhibit excellent water sterilization performance. Under optimal conditions, the PCN-224(Cu) MOFtors presented the best antibacterial performance of 99.4%, which improved by 23.4% compared to its static counterpart and 43.7% compared to static PCN-224(H). The underlying mechanism demonstrates that metal doping could increase the production of reactive oxygen species (ROS) and result in a more positive surface charge under light, which are short-distance effective sterilizing ingredients. Furthermore, the motion of MOFtors appears very important to extend the short-distance effective sterilization and thus synergistically improve the antibacterial performance. This work provides a new idea for preparing and developing light-driven MOFtors with multi-responsive properties.

Negative electrodes for supercapacitors with good performance using conductive bismuth-catecholate metal-organic frameworks.

Metal-organic frameworks (MOFs) have attracted increasing research interest in various fields. Unfortunately, the poor conductivity of most traditional MOFs considerably hinders their application in energy storage. Benefiting from the full charge delocalization in the atomic plane, two-dimensional conductive coordination frameworks achieve good electrochemical performance. In this work, π-π coupling conductive bismuth-catecholate nanobelts with tunable lengths, Bi(HHTP) (HHTP = 2,3,6,7,10,11-hexahydroxytriphenylene), are synthesized by a simple hydrothermal reaction and their length-dependent electrochemical properties are also investigated. The Bi(HHTP) nanobelts (about 10 μm in length) possess appropriate porosity, numerous redox active sites and good electrical conductivity. Being a negative electrode for supercapacitors, Bi(HHTP) nanobelts display a high specific capacitance of 234.0 F g-1 and good cycling stability of 72% after 1000 cycles. Furthermore, the mechanism of charge storage is interpreted for both battery-type and surface-capacitive behavior. It is believed that the results of this work will help to develop battery-type negative electrode materials with promising electrochemical performance using some newly designed π-π coupling conductive coordination frameworks.

Surface hydrophilicity modification of thin-film composite membranes with metal−organic frameworks (MOFs) Ti-UiO-66 for simultaneous enhancement of anti-fouling property and desalination performance

State-of-the-art desalination membranes are highly-related to the thin-film composite (TFC) type design, which usually based on a thin polyamide (PA) separation layer obtained by interfacial polymerization (IP) reaction on a thick support layer. However, the development of PA-TFC desalination membranes were limited by the well-known trade-off between water permeability and NaCl rejection as well as the membrane fouling issues. Traditional hydrophilic inorganic nano-modifiers would mitigate these two issues at the expenses of deteriorating membrane selectivity even triggering second-pollution to environment due to their low compatibility between inorganic materials and organic membrane bulk. Herein a bifunctional PA-TFC membrane modified by metal−organic frameworks (MOFs) Ti-UiO-66 was developed for simultaneous enhancement of anti-fouling property and desalination performance. Compared to the control PA-TFC membrane and the traditional MOF (UiO-66) modified TFC membrane, the optimised Ti-UiO-66 modified TFC membranes showed not only improved water permeability without sacrificing NaCl rejection after long-term chemical stability tests, but also obviously enhanced anti-fouling properties during forward osmosis process. Moreover, the introduction of Ti-UiO-66 into the PA separation layer of TFC membranes led to a less branched structure and reduced structural parameter (S value). The membrane performance was examined by ATR-FTIR, XRD, XPS, SEM and water contact angle (WCA) measurements. These results shed lights on a potential route of selecting advanced additives for TFC membranes to achieve enhanced desalination performance and anti-fouling property.

Mn-doped bimetallic synergistic catalysis boosts for enzymatic phosphorylation of N-Acetylglucosamine/ N-Acetylgalactosamine and their derivatives

Metal-organic frameworks (MOFs), as advanced enzyme immobilization platforms for improving biocatalysis and protein biophysics, are rarely investigated as solid supports in the enzymatic synthesis of carbohydrate and derivatives, which can be attributed to the complex biochemical reaction mechanisms and the adverse interactions between the high polarity of substrate sugars, glycoenzymes and traditional MOFs. Here, we introduced divalent metal ion Mn2+ into MOF to prepare bimetallic MOF microreactor that encapsulated N-acetylhexosamine 1-Kinase (NahK), a critical anomeric kinase involved in the enzymatic synthesis of sugar nucleotide. The introduced Mn ions not only adjusted the microstructure of MOFs, but also participated in the enzymatic catalysis as cofactor, thus facilitated the N-acetylglucosamine/ N-acetylgalactosamine (GlcNAc/GalNAc) phosphorylation. The Mn-doped NahK@Zn-metal organic material (MOM), integrated with high catalytic activity, high stability, and high recoverability, solved the issues of immobilization related to glucokinase activity. These features significantly improved the operability and reduced the processing cost, assuring industrial application prospects for sugar nucleotides synthesis.

Redox-Active Covalent Organic Frameworks with Nickel-Bis(dithiolene) Units as Guiding Layers for High-Performance Lithium Metal Batteries.

Combining the chemistry of metal-organic frameworks (MOFs) and covalent organic frameworks (COFs) can bring new opportunities for the design of advanced materials with enhanced tunability and functionality. Herein, we constructed two COFs based on Ni-bis(dithiolene) units and imine bonds, representing a bridge between traditional MOFs and COFs. The Ni-bis(dithiolene)tetrabenzaldehyde as the 4-connected linker was initially synthesized, which was further linked by 4-connected tetra(aminophenyl)pyrene (TAP) or 3-connected tris(aminophenyl)amine (TAA) linkers into two COFs, namely, Ni-TAP and Ni-TAA. Ni-TAP shows a two-dimensional sql network, while TAA is a twofold interpenetrated framework with an ffc topology. They both exhibit a high Brunauer-Emmett-Teller surface area (324 and 689 m2 g-1 for Ni-TAP and Ni-TAA, respectively), a fairly good conductivity (1.57 × 10-6 and 9.75 × 10-5 S m-1 for Ni-TAP and Ni-TAA, respectively), and high chemical stability (a stable pH window of 1-14 for Ni-TAA). When applied in lithium metal batteries as an intermediate layer for guiding the uniform Li electrodeposition, Ni-TAP and Ni-TAA displayed impressive lithiophilicity and high Li-ion conductivity, enabling the achievement of smooth and dense Li deposition with a clear columnar morphology and stable Li plating/stripping behaviors with high Li utilization, which is anticipated to pave the way to upgrade Li metal anodes for application in high-energy-density battery systems.

Two Dimensional Electrically Conductive Metal-Organic Frameworks

Metal-organic frameworks(MOFs) are a class of crystalline porous materials formed by self-assembly of metal ions or clusters and organic ligands through coordination bonds. Due to the high porosity and functional designability, MOFs have found wide applications of which make them widely used in various fields. However, most traditional MOFs have poor conductivity, which severely restricts their development in electrical related fields. In recent years, electrically conductive MOFs, especially two dimensional electrically conductive MOFs(2D ECMOFs), have attracted a great deal of research attention due to their semiconducting or metallic properties closely-related to their unique π-π stacking and π-d conjugation structures, which have great application potentials in electrical and energy related fields such as sensors, electronics, electrocatalysts, batteries, and supercapacitors. In this review, the recent progress in conducting mechanisms, structures, synthesis strategies and applications of 2D ECMOFs are summarized and highlighted. Furthermore, future challenges and opportunities based on the current research status are prospected.

Zeolitic imidazolate frameworks for use in electrochemical and optical chemical sensing and biosensing: a review.

This review (with 145 refs.) summarizes the progress that has been made in the use of zeolitic imidazolate frameworks in chemical sensing and biosensing. Zeolitic imidazolate frameworks (ZIFs) are a type of porous material with zeolite topological structure that combine the advantages of zeolite and traditional metal-organic frameworks. Owing to the structural flexibility of ZIFs, their pore sizes and surface functionalization can be reasonably designed. Following an introduction into the field of metal-organic frameworks and the zeolitic imidazolate framework (ZIF) subclass, a first large section covers the various kinds and properties of ZIFs. The next large section covers electrochemical sensors and assays (with subsections on methods for gases, electrochemiluminescence, electrochemical biomolecules). This is followed by main sections on ZIF-based colorimetric and luminescent sensors, with subsections on sensors for metal ions and anions, for gases, and for organic biomolecules. The last section covers SERS-based assays. Several tables are presented that give an overview on the wealth of methods and materials. A concluding section summarizes the current status, addresses current challenges, and gives an outlook on potential future trends. Graphical abstract In recent years, ZIFs and their composites have been widely used as probes in chemical sensing, and these probes have shown great advantages over other materials. This review describes the current progress on ZIFs toward electrochemical, luminescence, colorimetric, and SERS-based sensing applications, highlighting the different strategies for designing ZIFs and their composites and potential challenges in this field.

Facile synthesis of platinum-embedded zirconia/porous carbons tri-component nanohybrids from metal-organic framework and their application for ultra-sensitively detection of methyl parathion

Pt nanoparticles immobilized on zirconium oxide (ZrO2) and porous carbons (Pt/ZrO2/PCs) tri-component nanohybrids derived from Pt/ metal–organic frameworks (MOFs) were synthesized. They were prepared by using Pt/MOFs as a template. Additionally, MOFs (UiO-66, a traditional MOFs) were used as ZrO2 and carbon sources without the need of additional precursors. The formation of these composite materials was confirmed through a comprehensive characterization such as transmission electron microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy. The Pt/ZrO2/PCs show strong affinity toward the phosphate group and highly electrocatalytic activity for nitro compound on methyl parathion (MP) molecules. The high performance is owing to the combination of unique electrocatalytic activity of Pt species, excellent conductivity of PCs, and good adsorption properties of ZrO2 crystals for MP. The proposed Pt/ZrO2/PCs tri-component nanocomposite sensor realized the ultrasensitive detection of MP with a wide linear range between 3.8 × 10−9 and 1.14 × 10−2 mM and a low limit of detection of 1.45 × 10−9 mM. Therefore, it can be developed as an effective sensing platform for the detection of MP.