Synthesis Of Metal-organic Frameworks Research Articles

MOFs-Based Materials with Confined Space: Opportunities and Challenges for Energy and Catalytic Conversion.

Metal-Organic Frameworks (MOFs) are a very promising material in the fields of energy and catalysis due to their rich active sites, tunable pore size, structural adaptability, and high specific surface area. The concepts of "carbon peak" and "carbon neutrality" have opened up huge development opportunities in the fields of energy storage, energy conversion, and catalysis, and have made significant progress and breakthroughs. In recent years, people have shown great interest in the development of MOFs materials and their applications in the above research fields. This review introduces the design strategies and latest progress of MOFs are included based on their structures such as core-shell, yolk-shell, multi-shelled, sandwich structures, unique crystal surface exposures, and MOF-derived nanomaterials in detail. This work comprehensively and systematically reviews the applications of MOF-based materials in energy and catalysis and reviews the research progress of MOF materials for atmospheric water harvesting, seawater uranium extraction, and triboelectric nanogenerators. Finally, this review looks forward to the challenges and opportunities of controlling the synthesis of MOFs through low-cost, improved conductivity, high-temperature heat resistance, and integration with machine learning. This review provides useful references for promoting the application of MOFs-based materials in the aforementioned fields.

CO2-Based Stable Porous Metal-Organic Frameworks for CO2 Utilization.

The transformation of carbon dioxide (CO2) into functional materials has garnered considerable worldwide interest. Metal-organic frameworks (MOFs), as a distinctive class of materials, have made great contributions to CO2 capture and conversion. However, facile conversion of CO2 to stable porous MOFs for CO2 utilization remains unexplored. Herein, we present a facile methodology of using CO2 to synthesize stable zirconium-based MOFs. Two zirconium-based MOFs CO2-Zr-DEP and CO2-Zr-DEDP with face-centered cubic topology were obtained via a sequential desilylation-carboxylation-coordination reaction. The MOFs exhibit excellent crystallinity, as verified through powder X-ray diffraction and high-resolution transmission electron microscopy analyses. They also have notable porosity with high surface area (SBET up to 3688 m2 g-1) and good CO2 adsorption capacity (up to 12.5 wt %). The resulting MOFs have abundant alkyne functional moieties, confirmed through 13C cross-polarization/magic angle spinning nuclear magnetic resonance and Fourier transform infrared spectra. Leveraging the catalytic prowess of Ag(I) in diverse CO2-involved reactions, we incorporated Ag(I) into zirconium-based MOFs, capitalizing on their interactions with carbon-carbon π-bonds of alkynes, thereby forming a heterogeneous catalyst. This catalyst demonstrates outstanding efficiency in catalyzing the conversion of CO2 and propargylic alcohols into cyclic carbonates, achieving >99% yield at room temperature and atmospheric pressure conditions. Thus, this work provides a dual CO2 utilization strategy, encompassing the synthesis of CO2-based MOFs (20-24 wt % from CO2) and their subsequent application in CO2 capture and conversion processes. This approach significantly enhances overall CO2 utilization.

In-silico green toxicology approach toward discovering safer ligands for development of safe-by-design metal organic frameworks

: A vast variety of chemical compounds have been fabricated and commercialized, they not only result in industrial exposure during manufacturing and usage, but also have environmental impacts throughout their whole life cycle. Consequently, attempts to assess the risk of chemicals in terms of toxicology have never ceased. In-silico toxicology, also known as predictive toxicology, has advanced significantly over the last decade as a result of the drawbacks of experimental investigations. In this study, ProTox-III was applied to predict the toxicity of the ligands used for metal organic framework design and synthesis. Initially, 35 ligands, that have been frequently utilized for MOF synthesis and fabrication, were selected. Subsequently, canonical SMILES of ligands were extracted from the PUBCHEM database and inserted into the ProTox-III online server. Ultimately, webserver outputs including LD50 and the probability of toxicological endpoints (cytotoxicity, carcinogenicity, mutagenicity, immunotoxicity and ecotoxicity) were obtained and organized. According to retrieved LD50 data, the safest ligand was 5-hydroxyisophthalic. In contrast, the most hazardous ligand was 5-chlorobenzimidazole, with an LD50 of 8 mg/kg. Among evaluated endpoints, ecotoxicity was the most active and was detected in several imidazolate ligands. This data can open new horizons in design and development of green MOFs.

A Robust Pyrazolate Metal-Organic Framework for Efficient Catalysis of Dehydrogenative C-O Cross Coupling Reaction.

Construction of robust heterogeneous catalysts with atomic precision is a long-sought pursuit in the catalysis field due to its fundamental significance in taming chemical transformations. Herein, we present the synthesis of a single-crystalline pyrazolate metal-organic framework (MOF) named PCN-300, bearing a lamellar structure with two distinct Cu centers and one-dimensional (1D) open channels when stacked. PCN-300 exhibits exceptional stability in aqueous solutions across a broad pH range from 1 to 14. In contrast, its monomeric counterpart assembled through hydrogen bonding displays limited stability, emphasizing the role of Cu-pyrazolate coordination bonds in framework robustness. Remarkably, the synergy of the 1D open channels, excellent stability, and the active Cu-porphyrin sites endows PCN-300 with outstanding catalytic activity in the cross dehydrogenative coupling reaction to form the C-O bond without the "compulsory" ortho-position directing groups (yields up to 96%), outperforming homogeneous Cu-porphyrin catalysts. Moreover, PCN-300 exhibits superior recyclability and compatibility with various phenol substrates. Control experiments reveal the synergy between the Cu-porphyrin center and framework in PCN-300 and computations unveil the free radical pathway of the reaction. This study highlights the power of robust pyrazolate MOFs in directly activating C-H bonds and catalyzing challenging chemical transformations in an environmentally friendly manner.

Recent and Prospects of Synthesis and Application of Metal-Organic Frameworks (MOFs) in Water Treatment: A Review

AbstractWastewater treatment is designed to eradicate toxic pollutants emanating from the industrial effluent to the surface and underground water. The efficiency and limitations of most of the existing water treatment techniques such as coagulation/flocculation, photocatalysis, membrane technologies and adsorption in the remediation of toxic pollutants have been established. However, the success reported for each of these techniques is usually associated with the efficiency and environmental friendliness of water treatment products applied. MOFs-based products are one of the materials serving as an alternative to chemically synthesized products, and their application as water treatment products has been reported extensively but not systematically documented. In this review, authors endeavoured to comprehensively provide insights into the recent MOFs-based product synthesis for different applications, especially in water treatment. The key factors influencing the synthesis of MOFs, including choice of metal ions, organic linkers, and synthesis conditions, along with the latest developments in scalable and cost-effective fabrication techniques are discussed. The synthesis routes, their limitation and their performances as an adsorbent, photocatalyst and additives in membrane fabrication in the removal of toxic pollutants from water are elaborated. The prospects in the large-scale production of MOFs-based water treatment products for real industrial applications are critically reviewed in this study. Overall, a well-curated synthesis and application of MOFs in water treatment is hereby generated from the best resources accessible through the literature.

Heterogeneous strategy constructing a built-in electric field: CoP/FeP bifunctional electrode for overall water splitting

Development of non-noble bifunctional electrocatalysts for the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) are of great significance under alkaline electrolytes for overall water splitting. In this work, CoP/FeP has been designed and constructed in situ on carbon fiber paper by using the bimetallic metal organic frameworks (MOFs) synthesis strategy. The heterogeneous CoP/FeP displays excellent catalytic activities in both HER and OER of the fully hydrolyzed semi-reaction. Remarkably, CoP/FeP is applied as the bifunctional electrode in anode and cathode to construct an overall water splitting apparatus, resulting in the low cell voltage and excellent stability. The exceptional electrocatalytic performance may be mainly attributed to the heterogeneous interface, which constructs a built-in electric field to provide electron to Co with electron-rich structure, resulting in the strong adsorption of H and weak adsorption of O2 on Co. This study provides an effective and controllable method for the design of self-supporting bimetal phosphide catalysts.

One-pot synthesis of multivariate porphyrinic metal-organic frameworks with the insertion of metallobipyridine and the cooperative catalysis for carbonyl hydrosilylation

A series of multivariate porphyrinic metal-organic frameworks with the insertion of bipyridine were obtained via one-pot synthesis. The single Pt site was introduced into the bipyridine linker of BPy@Co-PCN-224 through post-synthetic metalation. The resultant Pt(BPy)Cl2@M-PCN-224, especially when M was Co(II), could efficiently promote carbonyl hydrosilylation with a turnover number up to 13,140 based on Pt and could be recycled and reused for at least 6 times without a noticeable decrease of activity. Mechanistic studies based on in situ UV–vis, FT-IR and 1H NMR spectra, and kinetic isotope effect (KIE) experiments disclosed that the catalytic reaction was accomplished by the cooperative catalysis of Pt(BPy)Cl2 and Co-PCN-224, in which Pt(BPy)Cl2 was the catalytically active center and meanwhile the Co-PCN-224 could condense and increase the concentrations of ketone molecules in its inner cavities through the interactions between Co-porphyrin and carbonyl group. The plausible reaction pathway was proposed based on density functional theory calculations.

Synthesis of fenugreek gum-based metal-organic framework (FG/Zr-AIPA MOF) composite beads for sequestration of heavy metal ions from aqueous solution.

Metal-organic frameworks (MOFs) are a prominent class of materials due to their large surface area and customized structures. This gives them specificity and high adsorption capacity while they lack mechanical strength and reusability. Integrating MOFs with polysaccharide matrix may retain MOF characteristics along with imparting structural integrity. In the present study, zirconium MOF-based fenugreek composite (FG/Zr-AIPA) beads were synthesised by a single droplet method and utilised for removal of Cr(VI), Pb(II) and Fe(III) from aqueous solution. The structure, morphology and composition of beads were evaluated by FTIR, XRD, TGA, BET, FESEM, EDX, XPS and zeta potential analysis. Adsorption isotherm, kinetics and thermodynamics were studied for Cr(VI), Pb(II) and Fe(III) adsorption. Adsorption kinetics and isotherm study revealed that all the metal ions were adsorbed through a monolayer chemisorption process. The maximum adsorption capacity was 344.43, 270.02 and 223.21mgg-1 for Cr(VI), Pb(II) and Fe(III), respectively, based on the Langmuir isotherm study. The thermodynamics study revealed that the interaction between the metal ions and the composite beads was spontaneous and endothermic. The FG/Zr-AIPA composite beads exhibited good reusability for the removal of Cr(VI), Pb(II) and Fe(III). The results open new possibilities for the preparation of polysaccharide MOF-based composite beads which exhibit substantial potential for water treatment applications.

Ultra-highly efficient adsorbent for CO2 capture from air by directional deprotonation regulation of MOFs-based amine grafting

In recent years, the solid amine of Metal-Organic Frameworks (MOFs) has shown promise as a direct air capture (DAC) adsorbent. However, the efficiency of amine groups under ultra-low CO2 concentrations requires improvement. In this study, we propose a novel method to regulate proton migration through solvent effects during amine grafting, to enhance the synthesis of MOFs as solid amine adsorbents and improve amine group utilization. This approach yielded outstanding results with a MIL-100(Cr)-based DAC adsorbent, demonstrating a CO2 adsorption capacity of 2.15 mmol/g and an ultra-high amine group utilization of 89.6 % at ambient conditions. By directional deprotonation regulation, the CO2 adsorption performance of the UiO-66(Zr)-based adsorbent significantly increased from 0.06 mmol/g of using H2O as solvent to 1.71 mmol/g of using NMP, with a 27.5-fold increase. Specifically, organic polar aprotic solvents enhanced the binding energy and reduced the energy barrier for deprotonation during the grafting process, thereby improving CO2 adsorption performance and amine group utilization, which shed a new light on the development of MOFs based CO2 adsorbent. Furthermore, due to the coordination of secondary amine groups with metal sites leads to the decrease of hydrophilic functional groups in the CO2 adsorption products, the hydrophobicity of products was reduced significantly resulting in an increase in the ΔS of the hydrated ion pairs after the adsorption, which reduced the heat of CO2 adsorption about 15 % than that reported in the literature. Based on changes in humidity conditions, the regeneration energy consumption of the MF-Cr-AEEA is less than 2.5 GJ/t CO2 under a relatively lower humidity, demonstrating outstanding industrial applications potential of the adsorbent.

Design and Synthesis of Bismuth-based Metal-Organic Frameworks for Photothermal Energy Conversion

Design and Synthesis of Bismuth-based Metal-Organic Frameworks for Photothermal Energy Conversion

Controlled Synthesis of Preferential Facet-Exposed Fe-MOFs for Ultrasensitive Detection of Peroxides.

Exposing different facets on metal-organic frameworks (MOFs) is highly desirable to enhance the performance for various applications, however, exploiting a concise and effective approach to achieve facet-controlled synthesis of MOFs remains challenging. Here, by modulating the ratio of metal precursors to ligands, the facet-engineered iron-based MOFs (Fe-MOFs) exhibits enhanced catalytic activity for Fenton reaction are explored, and the mechanism of facet-dependent performance is revealed in detail. Fully exposed (101) and (100) facets on spindle-shaped Fe-MOFs enable rapid oxidation of colorless o-phenylenediamine (OPD) to colored products, thereby establishing a dual-mode platform for the detection of hydrogen peroxide (H2O2) and triacetone triperoxide (TATP). Thus, a detection limit as low as 2.06nm is achieved, and robust selectivity against a wide range of common substances (>16 types) is obtained, which is further improved by incorporating a deep learning architecture with an SE-VGG16 network model, enabling precise differentiation of oxidizing agents from captured images. The present strategy is expected will shine light on both the rational synthesis of nanomaterials with modulated morphologies and the exploitation of high-performance trace chemical sensors.

Facile Layer Diffusion Technique for Synthesis of Terbium-Based Metal Organic Framework for Fluorometric Sensing of Hydroquinone.

A photoluminescent terbium (III)-based Metal Organic Framework (MOF) was synthesized at room temperature by layer diffusion method utilizing mixed carboxylate linkers (4,4'-oxybis(benzoic acid) and benzene-1,3,5 tricarboxylic acid). Synthesized MOF has crystalline nature and rod-shaped morphology and is thermally stable up to 455°C. The fluorescence emission spectra and theoretical results revealed that carboxylate linkers functioned as sensitizers for Tb(III) photoluminescence which resulted in four distinct emission peaks at 495, 547, 584, and 621nm corresponding to the transitions 5D4 → 7F6, 5D4 → 7F5, 5D4 → 7F4, and 5D4 → 7F3. Using synthesized MOF as fluorescent probe, hydroquinone was detected in aqueous medium with a detection limit of 0.048μM, remarkable recovery (95.6-101.1%), and relative standard deviation less than 2.25%. The quenching phenomenon may be ascribed to electron transfer from synthesized probe to oxidized hydroquinone via carboxylic groups on thesurface of MOF, which is further supported by photo-induced electron transfer mechanism. This study introduces a cheaper, faster, and more accurate method for hydroquinone detection.

Recent advances on metal-organic frameworks (MOFs) and their applications in energy conversion devices: Comprehensive review

Metal-organic frameworks (MOFs) have enticed huge interest over the years in a wide range of applications, including electrochemical energy storage/conversion devices, due to their controllable porous structure, tuneable composition, excellent thermal/chemical stabilities, and facile synthesis. However, conductivity enhancement and synthesis of redox-active MOFs are two key challenges hindering their large-scale applications in electrochemistry. Redox-active MOFs can be prepared using redox-active ligands and metal ions, which in turn leads to an additional benefit of π-stacking interactions. Conductivity improvements through favourable overlap of energy and orientation of both metal and ligand, π-π stacking, and the incorporation of a guest molecule to induce free charge carriers and reduce band gaps are key strategies. This review provides a detailed assessment of various synthesis techniques followed by post-production treatments to improve MOF's conductivity. Advancements in computational methods & machine learning for MOFs as well as the econmics of MOF's production are introduced. The use of MOFs and MOF-based nanomaterials in batteries, supercapacitors, and fuel cells, as well as the progress in using MOF and MOF-based catalysts for CO2 reduction and as a photocatalyst for hydrogen production, have been scrutinized by highlighting their benefits and shortcomings. Finally, the challenges MOFs and MOF-based materials face and their prospects when adopted as active materials in energy storage/conversion devices, as well as CO2 reduction and green hydrogen production, have also been elaborated.

Mechanochemical Synthesis and Three-Dimensional Electron Diffraction Structure Solution of a Novel Cu-Based Protocatechuate Metal-Organic Framework.

Mechanochemical synthesis is a powerful approach to obtain new materials, limiting costs, and times. However, defected and submicrometrical-sized crystal products make critical their characterization through classical single-crystal X-ray diffraction. A valid alternative is represented by three-dimensional (3D) electron diffraction, in which a transmission electron microscope is used, like a diffractometer. This work matches a green water-based mechanochemical synthesis and 3D electron diffraction to obtain and characterize a Cu-based protocatechuate metal-organic framework (PC-MOF). Its structure has been fully refined through dynamical diffraction theory, and free water molecules could be detected in the channels of the framework. Thermal characterization, focused on the dehydration profile determination, leads to the formation of a novel high-temperature 2D coordination polymer, fully solved with 3D electron diffraction data. At last, the strong activity of the PC-MOF against cationic dyes like methylene blue has been reported.

Synthesis of HER-capable cobalt metal organic framework using a straightforward reflux method and a thorough spectroscopic and theoretical analysis

A Cobalt MOF was obtained under reflux using aqueous methanol. The Cobalt MOF was synthesized using Cobalt (II) perchlorate hexahydrate and 1,3,5-Benzenetricarboxylic Acid (BTC) in a methanol mixed with double distilled water as a solvent under reflux condition for 2–3 h at 60–65 °C. The reddish solution obtained was filtered and kept in the refrigerator for almost 24 h. A crystal suitable for SC-XRD was obtained and the XRD analysis confirmed the polymeric structure of the Co-BTC. All the other analysis such as FTIR, Thermal analysis and FESEM of Co-BTC was carried out. Further, the efficacy of it as a potential catalyst towards HER was explored. The theoretical study assisted, and the data suggests that low band gap of the MOF possibly favors its efficacy in the Hydrogen Evolution Reaction (HER).

Metal‐Organic Framework‐Based Composites for Rapid and Sensitive Virus Detection: Current Status and Future Prospective

AbstractThe current spread of various viruses has negatively affected human life and health. Developing enhanced virus diagnostic techniques to mitigate future outbreaks is becoming vital. Metal‐organic frameworks (MOFs) have gained significant attention for their potential applications in virus detection because of their outstanding features, including high surface area, tunable properties, and adjustable pore size. Integrating nanomaterials with MOFs can also further enhance these properties, creating a new class of materials referred to as MOF‐based nanocomposites. This review paper provides an overview of the MOF‐based nanocomposites' status and future prospects for enhanced virus detection. The recent advances in the synthesis and functionalization of MOF and MOF‐based nanocomposites for virus detection are discussed. The paper describes the different types of detection platforms, including nucleic acid and immunological detection, as well as the mechanisms of MOF‐based sensors and the techniques used to synthesize MOFs and MOF‐based nanocomposites for virus detection. Additionally, the review paper explores the potential of integrating MOFs into real sensing devices and their prospects in real‐life applications. Finally, the paper examines the current challenges of these biosensing platforms. Overall, the review paper highlights the capability of MOFs and MOF‐based nanocomposites as versatile and practical platforms for virus detection and provides a comprehensive overview of the latest advancements in this area of research.

Synthesis and adsorption properties of new calcium metal-organic framework (Ca-MOF) ZIOC-10 based on a new carbazole linker

A carbazole-based linker 9-(carboxymethyl)carbazole-3,6-dicarboxylic acid (H3cbzac) was synthesized for the first time. Its structure was confirmed via 1H NMR and Powder X-Ray Difraction (PXRD) methods. A novel calcium-based 2D MOF Ca(H2cbzac)2(DMF)2 (ZIOC-10) was synthesized via a solvothermal procedure. It was found that the obtained framework undergoes several structural changes upon heating, which lead to the formation of a new framework Ca(H2cbzac)2 (ZIOC-10a). Noteworthy, ZIOC-10 transforms into the permanent porous (524 m2/g) 3D framework, which can absorb methane, ethane, propane, and carbon dioxide at room temperature.

Metal-organic skeleton derived RuCoMoCuOx/C porous nanosheet as an efficient dual-function electrocatalyst for superior water decomposition

Polymetallic composites can significantly affect the structure and active sites of materials. In this study, we prepared polymetallic organic structures using a metal-organic framework (MOF) synthesis strategy and a hydrothermal method. We controlled and adjusted the ratio of metals to create precursors, which were then calcined to produce targeted polymetallic oxides. The polymetallic oxides prepared (RuCoMoCuOx/C) demonstrated excellent properties for both HER and OER in 1.0 M KOH, with an overpotential of 136 mV @ 10 mA cm−2 for HER and 296 mV @ 10 mA cm−2 for OER. The efficient catalytic performance of dual hydrolysis is attributed to the lamellar porous structure of RuCoMoCuOx/C and the synergistic effect of each metal element in the polymetallic catalyst. DFT theoretical calculations show that when H2O molecules adsorb around Ru, Co, and Mo sites, OH* adsorbs at electron-deficient centers, while H+ is more readily adsorbed by electron-rich Cu sites. This unique configuration is more conducive to water dissociation.

Synthesis and evaluation of mixed 3d transition metal organic frameworks for energy application

Mixed metal-organic frameworks (MOFs) have generated considerable interest in the field of energy storage and conversion, attributed to their synergistic effects and exceptional electro chemical performance. In this work, a series of bimetallic-MOFs were synthesized utilizing same organic component i.e. benzene-1, 4-dicarboxylic acid (BDC) and changing the metal ions viz. Cu/Fe, Cu/Co, Cu/Ni and Cu/Zn, envisaging synergistic catalysing performance by various metal ions. All the synthesized MOFs were characterized, and the parameters were optimized. Under optimal experimental conditions, among the various MOFs examined, Cu/Co-BDC MOF exhibited the highest specific capacitance of 1892 Fg−1 at a scan rate of 1 mVs−1 with the energy density of 95.78 Whkg−1 and power density of 1915 Wkg−1. This material displayed exceptional supercapacitance performance, characterized by a superior capacitive retention of 85.5% even after 5000 cycles. These finding highlight its potential suitability for super capacitor applications.

Rapid, Massive, and Green Synthesis of Polyoxometalate-Based Metal-Organic Frameworks to Fabricate POMOF/PAN Nanofiber Membranes for Selective Filtration of Cationic Dyes.

Developing high-efficiency membrane materials for the rapid removal of organic dyes is crucial but remains a challenge. Polyoxometalates (POMs) clusters with anionic structures are promising candidates for the removal of cationic dyes via electrostatic interactions. However, their shortcomings, such as their solubility and inability to be mass-produced, hinder their application in water pollution treatment. Here, we propose a simple and green strategy utilizing the room temperature stirring method to mass produce nanoscale polyoxometalate-based metal-organic frameworks (POMOFs) with porous rhomboid-shaped dodecahedral and hexagonal prism structures. The products were labeled as POMOF1 (POMOF-PW12) and POMOF2 (POMOF-PMo12). Subsequently, a series of x wt% POMOF1/PAN (x = 0, 3, 5, and 10) nanofiber membranes (NFMs) were prepared using electrospinning technology, where polyacrylonitrile (PAN) acts as a "glue" molecule facilitating the bonding of POMOF1 nanoparticles. The as-prepared samples were comprehensively characterized and exhibited obvious water stability, as well as rapid selective adsorption filtration performance towards cationic dyes. The 5 wt% POMOF1/PAN NFM possessed the highest removal efficiency of 96.7% for RhB, 95.8% for MB, and 86.4% for CV dyes, which realized the selective separation over 95% of positively charged dyes from the mixed solution. The adsorption mechanism was explained using FT-IR, SEM, Zeta potential, and adsorption kinetics model, which proved that separation was determined via electrostatic interaction, hydrogen bonding, and π-π interactions. Moreover, the POMOF1/PAN membrane presented an outstanding recoverable and stable removal rate after four cycles. This study provides a new direction for the systematic design and manufacture of membrane separation materials with outstanding properties for contaminant removal.