Multiple Functions of Gas Separation and Vapor Adsorption in a New MOF with Open Tubular Channels

Separation or purification is one of the difficult problems in the petrochemical industry. To help solve the difficulty of separation or purification for C₂H₂/CO₂ and C₂H_n/CH₄ in the chemical industry, we synthesized a new metal-organic framework (MOF), [Ni(dpip)]·2.5DMF·H₂O (1), by a bipyridyl-substituted isophthalic acid ligand. The MOF includes two types of one-dimensional (1D) tubular channels with different sizes and porous environments. The unique tubular channels lead to not only remarkable gas sorption capacity of C₂H₄, C₂H₂, and CO₂, but also good selectivity for C₂H₂/CH₄, C₂H₂/CH₄, CO₂/CH₄, and C₂H₂/CO₂, as demonstrated by single-component sorption isotherm results, ideal adsorbed solution theory calculations, and dynamic breakthrough curves. Grand canonical Monte Carlo (GCMC) simulation reveals preferential adsorption sites in the MOF for CO₂, C₂H₂, and C₂H₄. The MOF also exhibits an obvious size-selective absorption effect on vapor molecules.

Recent advances in process engineering and upcoming applications of metal-organic frameworks

Progress in metal-organic frameworks (MOFs) has advanced from fundamental chemistry to engineering processes and applications, resulting in new industrial opportunities. The unique features of MOFs, such as their permanent porosity, high surface area, and structural flexibility, continue to draw industrial interest outside the traditional MOF field, both to solve existing challenges and to create new businesses. In this context, diverse research has been directed toward commercializing MOFs, but such studies have been performed according to a variety of individual goals. Therefore, there have been limited opportunities to share the challenges, goals, and findings with most of the MOF field. In this review, we examine the issues and demands for MOF commercialization and investigate recent advances in MOF process engineering and applications. Specifically, we discuss the criteria for MOF commercialization from the views of stability, producibility, regulations, and production cost. This review covers progress in the mass production and formation of MOFs along with future applications that are not currently well known but have high potential for new areas of MOF commercialization.

Luminescence response mode and chemical sensing mechanism for lanthanide-functionalized metal–organic framework hybrids

This comprehensive review systematically summarizes the luminescence response mode and chemical sensing mechanism for lanthanide-functionalized MOF hybrids (abbreviated as LnFMOFH).

Enabling photocatalytic activity of [Ru(2,2′:6′,2′′-terpyridine)2]2+ integrated into a metal–organic framework

A multicomponent metal–organic framework is constructed to incorporate the bis-terpyridyl ruthenium motif, which was considered poorly photoactive, through a stepwise reticular synthesis to arouse its photosensitiveness for producing singlet oxygen.

Incorporation of homogeneous organometallic catalysts into metal–organic frameworks for advanced heterogenization: a review

The heterogenization of homogeneous organometallic catalysts by incorporation into MOFs using different strategies, MOF selection, OMC selection, and the use of hybrid heterogeneous catalysts OMC@MOFs in catalytic applications are summarized and discussed.

Varied proton conductivity and photoreduction CO2 performance of isostructural heterometallic cluster based metal–organic frameworks

A family of isostructural heterometallic MOFs based on Fe2M clusters serve as potential proton conductors and photocatalysts for CO2 photoreduction.

A new strategy for the adsorption and removal of fenitrothion from real samples by active-extruded MOF (AE-MOF UiO-66) as an adsorbent

The adsorption and removal of hazardous materials such as fenitrothion by adsorbents with high adsorption capacities and easy separation from sample solutions are highly desirable.

Construction of a superhydrophobic microenvironment via polystyrene coating: an unexpected way to stabilize CuI against oxidation

A superhydrophobic microenvironment in MIL-101(Cr) was constructed via coating polystyrene, resulting in improved CuI stability and adsorptive desulfurization performance.

Can 3D electron diffraction provide accurate atomic structures of metal–organic frameworks?

Structure determination by continuous rotation electron diffraction can be as feasible and accurate as single crystal X-ray diffraction without the need for large crystals.

The state of the field: from inception to commercialization of metal–organic frameworks

We provide a brief overview of the state of the MOF field from their inception to their synthesis, potential applications, and finally, to their commercialization.

Capture and Decomposition of the Nerve Agent Simulant, DMCP, Using the Zeolitic Imidazolate Framework (ZIF-8)

Understanding mechanisms of decontamination of chemical warfare agents (CWA) is an area of intense research aimed at developing new filtration materials to protect soldiers and civilians in case of state-sponsored or terrorist attack. In this study, we employed complementary structural, chemical, and dynamic probes and in situ data collection, to elucidate the complex chemistry, capture, and decomposition of the CWA simulant, dimethyl chlorophosphonate (DMCP). Our work reveals key details of the reactive adsorption of DMCP and demonstrates the versatility of zeolitic imidazolate framework (ZIF-8) as a plausible material for CWA capture and decomposition. The in situ synchrotron-based powder X-ray diffraction (PXRD) and pair distribution function (PDF) studies, combined with Fourier transform infrared (FT-IR) spectroscopy, X-ray photoelectron spectroscopy (XPS), zinc K-edge X-ray absorption near edge structure (XANES), and Raman spectroscopies, showed that the unique structure, chemical state, and topology of ZIF-8 enable accessibility, adsorption, and hydrolysis of DMCP into the pores and revealed the importance of linker chemistry and Zn²⁺ sites for nerve agent decomposition. DMCP decontamination and decomposition product(s) formation were observed by thermogravimetric analysis, FT-IR spectroscopy, and phosphorus (P) K-edge XANES studies. Differential PDF analysis indicated that the average structure of ZIF-8 (at the 30 Å scale) remains unchanged after DMCP dosing and provided information on the dynamics of interactions of DMCP with the ZIF-8 framework. Using in situ PXRD and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), we showed that nearly 90% regeneration of the ZIF-8 structure and complete liberation of DMCP and decomposition products occur upon heating.

In vitro human skin decontamination efficacy of MOF-808 in decontamination lotion following exposure to the nerve agent VX

Metal-organic frameworks (MOFs) have shown promising properties for removal of chemical warfare agents, in particular for material decontamination and functionalized fabrics. The MOF-properties could also be beneficial for skin decontamination, especially when exposed to highly toxic and low volatile nerve agents. In such exposures, efficient decontamination is crucial for adequate medical management. In the present study, seven zirconium-based MOFs were evaluated for their ability to degrade VX and subsequently tested in vitro for decontamination of VX on human dermatomed skin. Of the MOFs evaluated, MOF-808 showed the greatest ability to degrade VX in an alkaline buffer with complete degradation of VX within 5 min. PCN-777, Zr-NDC and NU-1000 displayed degradation half-lives of approximately 10 min. When including MOF-808 in a skin friendly carrier with slightly acidic pH, a decreased agent degradation rate was observed, requiring over 24 h to reach complete degradation. In skin decontamination experiments, MOF-808 enhanced the efficacy compared to the carrier alone, essentially by improved agent absorption. Adding MOF-808 to Reactive Skin Decontamination Lotion (RSDL) did not improve the high effectiveness of RSDL alone. The present study showed that including MOF in skin decontamination lotions could be beneficial. Further studies should include optimizing the particulates and formulations.

Emerging Porous Materials and Their Composites for NH3 Gas Removal

NH3, essential for producing artificial fertilizers and several military and commercial products, is being produced at a large scale to satisfy increasing demands. The inevitable leakage of NH3 during its utilization, even in trace concentrations, poses significant environmental and health risks because of its highly toxic and reactive nature. Although numerous techniques have been developed for the removal of atmospheric NH3, conventional NH3 abatement systems possess the disadvantages of high maintenance cost, low selectivity, and emission of secondary wastes. In this context, highly tunable porous materials such as metal-organic frameworks, covalent organic frameworks, hydrogen organic frameworks, porous organic polymers, and their composite materials have emerged as next-generation NH3 adsorbents. Herein, recent progress in the development of porous NH3 adsorbents is summarized; furthermore, factors affecting NH3 capture are analyzed to provide a reasonable strategy for the design and synthesis of promising materials for NH3 abatement.

Metal-organic framework for the extraction and detection of pesticides from food commodities

Pesticide residues in food matrices, threatening the survival and development of humanity, is one of the critical challenges worldwide. Metal-organic frameworks (MOFs) possess excellent properties, which include excellent adsorption capacity, tailorable shape and size, hierarchical structure, numerous surface-active sites, high specific surface areas, high chemical stabilities, and ease of modification and functionalization. These promising properties render MOFs as advantageous porous materials for the extraction and detection of pesticides in food samples. This review is based on a brief introduction of MOFs and highlights recent advances in pesticide extraction and detection through MOFs. Furthermore, the challenges and prospects in this field are also described.

Stretchable Electrochemical Biosensing Platform Based on Ni-MOF Composite/Au Nanoparticle-Coated Carbon Nanotubes for Real-Time Monitoring of Dopamine Released from Living Cells

Existing electrochemical biosensing platforms, using traditional rigid and unstretchable electrodes, cannot monitor the biological signaling molecules released by cells in a mechanically deformed state in real time. Here, a stretchable and flexible electrochemical sensor was developed based on nickel metal-organic framework composite/Au nanoparticle-coated carbon nanotubes (Ni-MOF composite/AuNPs/CNTs) for sensitive detection of dopamine (DA) released by C6 living cells in real time. A Ni-MOF composite was obtained by introducing Ni, NiO, and a carbon frame onto the surface of two-dimensional (2D) Ni-MOF nanosheets using an efficient one-step calcination method. The hybrid of Ni-MOF composite/AuNPs/CNTs that deposited on the poly(dimethylsiloxane) (PDMS) film endowed the sensor with excellent electrochemical performance with a wide linear range of 50 nM to 15 μM and a high sensitivity of 1250 mA/(cm² M) and also provided the sensor with desirable stability against mechanical deformation. Furthermore, the stretchable electrode also displayed good cellular compatibility while C6 living cells can be cultured and proliferated on it with strong adhesion. Then, the DA released by C6 living cells with chemical induction in both natural and stretched states was monitored using our stretchable and flexible electrochemical sensor in real time. This indicates that our new design of flexible Ni-MOF composite/AuNPs/CNTs/PDMS (NACP) film electrodes provides more opportunities for the detection of chemical signals released from cells and soft living organisms even under mechanically deformed states.

Benign Integration of a Zn-Azolate Metal-Organic Framework onto Textile Fiber for Ammonia Capture

Ammonia (NH₃) exposure has a serious impact on human health because of its toxic and corrosive nature. Therefore, efficient personal protective equipment (PPE) such as masks is necessary to eliminate and mitigate NH₃ exposure risks. Because economically and environmentally viable conditions are of interest for large-scale manufacture of PPE, we herein report a benign procedure to synthesize a Zn-azolate metal-organic framework (MOF), MFU-4, for NH₃ capture. The surface area and morphology of MFU-4 obtained in alcohol solvents at room temperature is consistent with that of traditionally synthesized MFU-4 in N,N-dimethylformamide at 140 °C. In addition to its large NH₃ uptake capacity at 1 bar (17.7 mmol/g), MFU-4 shows outstanding performance in capturing NH₃ at low concentration (10.8 mmol/g at 0.05 bar). Furthermore, the mild synthetic conditions implemented make it facile to immobilize MFU-4 onto cotton textile fiber. Enhanced NH₃ capture ability of the MFU-4/fiber composite was also attributed to the well-exposed MOF particles. The benign synthetic MFU-4 procedure, high NH₃ uptake, and easy integration onto fiber pave the way toward implementation of similar materials in PPE.

Capture of Sulfur Mustard by Pillar[5]arene: From Host-Guest Complexation to Efficient Adsorption Using Nonporous Adaptive Crystals

Sulfur mustard (SM) has been the most frequently used chemical warfare agent. Here, we present the efficient containment of SM and its simulants by per-ethylated pillar[5]arene (EtP5). EtP5 exhibited strong binding abilities toward SM and its simulants not only in solution but also in the solid state. The association constant (Ka) between SM and EtP5 was determined as (6.2 ± 0.6) × 103 M-1 in o-xylene-d10. Single crystal structure of SM@EtP5 showed that a 1:1 inclusion complex was formed, which was driven by multiple C-H···π/Cl/S and S···π interactions. In addition, activated crystal materials of EtP5 (EtP5α) could effectively adsorb SM simulants at solid-vapor phase; powder X-ray diffraction patterns and host-guest crystal structures indicated that the uptake process triggered a solid-state structural transformation. More interestingly, the captured guest molecules could be stably contained in EtP5α for at least 6 months in air at room temperature.

Microwave-Assisted Solvothermal Synthesis of UiO-66-NH2 and Its Catalytic Performance toward the Hydrolysis of a Nerve Agent Simulant

Zr-containing metal-organic frameworks (MOFs) exhibit a good performance of catalyzing the hydrolysis of chemical warfare agents, which is closely related to the size of MOF particles and its defects, but these two factors are often intertwined. In this article, we synthesized UiO-66-NH2 nanoparticles using a microwave-assisted hydrothermal method. By using a new modulator 4-Fluoro-3-Formyl-Benzoic Acid (FFBA) in different proportions, MOF particles with the same defect degree but different scales and those with similar sizes but different defect degrees can be obtained. The performance of the obtained MOF particles to catalyze the hydrolysis of the nerve agent simulant, dimethyl 4-nitrophenyl phosphate (DMNP), was investigated, and the effects of single factors of size or defect were compared for the first time. As the size of the obtained MOF particles increased from 81 nm to 159 nm, the catalytic degradation efficiency toward DMNP gradually decreased, and the half-life increased from 3.9 min to 11.1 min. For MOFs that have similar crystal sizes, the catalytic degradation half-life of MOF3 is only 5 min, which is much smaller than that of MOF5 due to the defects increase from 1.2 to 1.8 per Zr6 cluster.

A Water-Stable Cationic Metal-Organic Framework with Hydrophobic Pore Surfaces as an Efficient Scavenger of Oxo-Anion Pollutants from Water

Water contamination due to heavy metal-based toxic oxo-anions (such as CrO₄^2- and TcO₄^-) is a critical environmental concern that demands immediate mitigation. Herein, we present an effort to counter this issue by a novel chemically stable cationic metal-organic framework (iMOF-2C) with strategic utilization of a ligand with hydrophobic core, known to facilitate such oxo-anion capture process. Moreover, the compound exhibited very fast sieving kinetics for such oxo-anions and a very high uptake capacity for CrO₄^2- (476.3 mg g^-1) and ReO₄^- (691 mg g^-1), while the latter being employed as a surrogate analogue for radioactive TcO₄^- anions. Notably, the compound showed excellent selectivity even in the presence of other competing anions such as NO₃^-, Cl^-, SO₄^2-, ClO₄^-. etc.. Furthermore, the compound possesses excellent reusability (up to 10 cycles) and is also employed to a stationary phase ion column to decontaminate the aforementioned oxo-anions from water.

Luminescent triphenylamine-based metal-organic frameworks: recent advances in nitroaromatics detection

Luminescent metal-organic frameworks (LMOFs), as one branch of MOFs, have attracted considerable attention in recent years due to their good crystallinity, structural diversity, tunable porosity and easily induced fluorescence emission. Importantly, their photoluminescence (PL) properties can be adjusted by altering metal ions or metal clusters and organic ligands in one hybrid system. Among the various sensing applications, using LMOFs as chemical sensors to detect the explosive and environment pollution causing nitroaromatic compounds (NACs) is an important topic. In this account, we describe the recent advancements in the field of NAC detection by LMOFs based on the triphenylamine (TPA) unit as the π-conjugated fluorophore.

Enhanced removal for H2S by Cu-ordered mesoporous carbon foam

It is of great significance to protect workers from Sulphur compounds in efficient ways during the regular overhaul or emergency management. Efficient adsorbent with low pressure drop is highly desired in protective equipment. In this work, Cu-ordered mesoporous carbon foams (MeCF) were prepared through the sol-gel casting and wet-impregnation process. The obtained carbon foams possessed typical sponge structure with high porosity and copper particles attached on the skeleton. The characterization on morphology, structure and property illustrated that the presence of mesopores could effectively inhibit the growth of copper particle on MeCF. As the representative of Sulphur compounds, H₂S was selected to evaluate the protective performance. Porous copper carbon foams with moderate loading rate (3%) of copper species exhibited longest breakthrough time and largest adsorption capacity. Compared with the microporous foams, MeCF-3 displayed promoted protective performance with breakthrough time of 54.7 min and adsorption capacity of 27.8 mg/g. The enhancement on capabilities was attributed to small-sized copper species with high activity and better dispersion on mesoporous structure. These results reveled that MeCF with sponge frameworks, developed mesoporous structure and high dispersion of active species would be a promising candidate for the elimination of H₂S in personal protective equipment.

Water and Metal-Organic Frameworks: From Interaction toward Utilization

The steep stepwise uptake of water vapor and easy release at low relative pressures and moderate temperatures together with high working capacities make metal-organic frameworks (MOFs) attractive, promising materials for energy efficient applications in adsorption devices for humidity control (evaporation and condensation processes) and heat reallocation (heating and cooling) by utilizing water as benign sorptive and low-grade renewable or waste heat. Emerging MOF-based process applications covered are desiccation, heat pumps/chillers, water harvesting, air conditioning, and desalination. Governing parameters of the intrinsic sorption properties and stability under humid conditions and cyclic operation are identified. Transport of mass and heat in MOF structures, at least as important, is still an underexposed topic. Essential engineering elements of operation and implementation are presented. An update on stability of MOFs in water vapor and liquid systems is provided, and a suite of 18 MOFs are identified for selective use in heat pumps and chillers, while several can be used for air conditioning, water harvesting, and desalination. Most applications with MOFs are still in an exploratory state. An outlook is given for further R&D to realize these applications, providing essential kinetic parameters, performing smart engineering in the design of systems, and conceptual process designs to benchmark them against existing technologies. A concerted effort bridging chemistry, materials science, and engineering is required.

Decomposition of Chemical Warfare Agent Simulants Utilizing Pyrolyzed Cotton Balls as Wicks

A simple method to improve the thermal decomposition of chemical warfare agent simulants is reported. Utilizing pyrolyzed cotton balls as a substrate for the delivery of an incendiary agent into a bulk volume of chemical warfare agent simulants, significant enhancements in the burning rates were achieved with respect to either other wicks or the incendiary agent by itself. To perform the decomposition experiments and follow the reaction in real time, while still addressing the important safety considerations related to experiments involving chemical warfare agent simulants and incendiary agents, a simple instrument was assembled in a laboratory hood, where all experiments were performed. Under ambient conditions, this method was able to enhance the decomposition of simulants for both sulfur mustard (HD) and sarin (GB) chemical warfare agents. Overall, the proposed approach represents one of the simplest and more cost-effective ways to improve the decomposition of these dangerous substances, presenting options for field expedient and low-cost processes that could be applied in the near future to the safe destruction of an actual CWA.

Applications of pair distribution function analyses to the emerging field of non-ideal metal-organic framework materials

Pair distribution function, PDF, analyses are emerging as a powerful tool to characterize non-ideal metal-organic framework (MOF) materials with compromised ordering. Although originally envisaged as crystalline porous architectures, MOFs can incorporate defects in their structures through either chemistry or mechanical stress, resulting in materials with unpredicted novel properties. Indeed, a wide variety of current non-ideal MOFs have disorder in their structures to some extent, thereby often lacking crystals. Typically, PDF experiments are performed using high-energy synchrotron X-rays or neutrons to achieve a superior high atomic resolution in short times. The PDF technique analyses both Bragg and diffuse scattering signals simultaneously, without being restricted to crystalline materials. This characteristic makes PDF analyses a powerful probe to address the structural characterization of non-ideal MOF materials both at the local and intermediate range scales, including under in situ conditions relevant to MOF synthesis, activation and catalysis.

Exploring the Effects of Node Topology, Connectivity, and Metal Identity on the Binding of Nerve Agents and Their Hydrolysis Products in Metal-Organic Frameworks

Recent studies have shown that metal-organic frameworks (MOFs) built from hexanuclear M(IV) oxide cluster nodes are effective catalysts for nerve agent hydrolysis, where the properties of the active sites on the nodes can strongly influence the reaction energetics. The connectivity and metal identity of these M₆ nodes can be easily tuned, offering extensive opportunities for computational screening to predict promising new materials. Thus, we used density functional theory (DFT) to examine the effects of node topology, connectivity, and metal identity on the binding energies of multiple nerve agents and their corresponding hydrolysis products. By computing an optimization metric based on the relative binding strengths of key hydrolysis reaction species (water, agent, and bidentate-bound products), we predicted optimal M₆ nodes for hydrolyzing specific nerve agent and simulant molecules, where our results are in qualitative agreement with observed experimental trends. This analysis highlighted the notion that no single metal or node topology is optimal for all possible organophosphates, suggesting that MOFs should be selected based on the agent of interest. Using the large amount of data generated from our DFT calculations, we then derived quantitative structure-activity relationship (QSAR) models to help explain the complex trends observed in the binding energies. Through linear regression, we identified the most important descriptors for describing the binding of nerve agents and their hydrolysis products to M₆ nodes. These results suggested that both molecular and node properties, including both structural and chemical features, collectively contribute to the binding energetics. By performing a thorough statistical analysis, we showed that our QSAR models are capable of making quantitatively accurate binding energy predictions for nerve agents and their hydrolysis products in a wide variety of M(IV)-MOFs. The insights gained herein can be used to guide future experiments for the synthesis of MOFs with enhanced catalytic activity for organophosphate hydrolysis.

Functionalization effects on HKUST-1 and HKUST-1/graphene oxide hybrid adsorbents for hydrogen sulfide removal

HKUST-1, a Cu-based metalorganic framework (MOF), was synthesized solvothermally, functionalized with polyethyleneimine (PEI), and hybridized with graphene oxide (GO) and functionalized GO for H₂S removal. MOF synthesis approach, molecular weight of amines, and the content of GO in the hybrid adsorbents were systematically varied. The adsorbent materials were characterized by XRD, FTIR, SEM, elemental analysis, liquid N₂ adsorption-desorption, water vapor and oxygen sorption, and subsequently tested for H₂S adsorption in a breakthrough column. The MOF in the composite adsorbents consisting of in-situ grown HKUST-1 on GO that was pre-functionalized with low molecular weight PEI exhibited the highest H₂S adsorption uptake at ambient conditions (0.9 mmol S g^-1 MOF) in comparison to 0.5 mmol S g^-1 MOF for the parent HKUST-1, thus showing an 80 % increase in uptake, while this material also exhibited significantly enhanced sorption kinetics. H₂S adsorption at higher temperature (150 °C) was also performed, and at this temperature a HKUST/GO hybrid adsorbent resulted in the highest MOF capacity, i.e. 2.1 mmol S g^-1 MOF, which is 27 % higher than that of the parent MOF at the same conditions. Formation of hybrid adsorbents with GO coupled to tunable functionalization of both GO support and the MOF crystallites can contribute in optimizing H₂S capture performance of MOFs.

Photothermal graphene/UiO-66-NH2 fabrics for ultrafast catalytic degradation of chemical warfare agent simulants

Lightweight and wearable fabrics with rapid self-detoxification functions are highly desired to resist chemical warfare agents (CWAs). Metal organic frameworks (MOFs) with high specific surface area and customizability are singularly attractive because of their ability to effectively capture and catalytically degrade CWAs. Herein, photothermal graphene-based nanocomposite fabrics are designed by wet-spinning and chemical reduction of graphene oxide fibers followed by in situ growth of UiO-66-NH₂. The flexible graphene fabrics decorated with UiO-66-NH₂ nanoparticles exhibit an ultrafast photothermal catalytic decontamination of dimethyl 4-nitrophenyl phosphate (DMNP), a typical simulant of CWAs. The half-life of the degradation reaction decreases from 3.4 to 1.6 min under simulated solar light irradiation, a significant gain over the values reported in the literature. Furthermore, DMNP can be degraded in 20 min by the graphene/UiO-66-NH₂ fabric, and even after 5 cycles the degradation efficiency still retains more than 92 %. More importantly, the photothermal conversion of graphene and its instantaneous heat transfer to the UiO-66-NH₂ catalyst effectively accelerate the catalytic reaction kinetics, achieving the fast detoxification of DMNP. The combination of catalytic degradation of MOFs with photothermal conversion effect of graphene makes the lightweight and flexible fabrics promising for protection against CWAs and other pollutants.

Targeted classification of metal-organic frameworks in the Cambridge structural database (CSD)

Large-scale targeted exploration of metal–organic frameworks (MOFs) with characteristics such as specific surface chemistry or metal-cluster family has not been investigated so far.

Large-scale targeted exploration of metal–organic frameworks (MOFs) with characteristics such as specific surface chemistry or metal-cluster family has not been investigated so far. These definitions are particularly important because they can define the way MOFs interact with specific molecules (e.g. their hydrophilic/phobic character) or their physicochemical stability. We report here the development of algorithms to break down the overarching family of MOFs into a number of subgroups according to some of their key chemical and physical features. Available within the Cambridge Crystallographic Data Centre's (CCDC) software, we introduce new approaches to allow researchers to browse and efficiently look for targeted MOF families based on some of the most well-known secondary building units. We then classify them in terms of their crystalline properties: metal-cluster, network and pore dimensionality, surface chemistry (i.e. functional groups) and chirality. This dynamic database and family of algorithms allow experimentalists and computational users to benefit from the developed criteria to look for specific classes of MOFs but also enable users – and encourage them – to develop additional MOF queries based on desired chemistries. These tools are backed-up by an interactive web-based data explorer containing all the data obtained. We also demonstrate the usefulness of these tools with a high-throughput screening for hydrogen storage at room temperature. This toolbox, integrated in the CCDC software, will guide future exploration of MOFs and similar materials, as well as their design and development for an ever-increasing range of potential applications.

Co-Fe-layered double hydroxide decorated amino-functionalized zirconium terephthalate metal-organic framework for removal of organic dyes from water samples

In this study, a new efficient adsorbent of Co-Fe-layered double hydroxides@metal-organic framework (Co-Fe-LDH@UiO-66-NH₂) was synthesized and used for extraction of methylene blue (MB) and methylene red (MR) from water samples prior to their determination by UV-Vis spectrophotometer. The adsorbent was characterized by Fourier Transform Infrared Spectroscopy (FT-IR), Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray (EDX), X-ray Diffraction (XRD), and Brunauer-Emmett-Teller (BET) analyses. The impact of various parameters such as pH of the aqueous phase, extraction time, amount of adsorbent, type and volume of eluent solvent, desorption time, and sample volume were studied. The maximum extraction recovery was obtained at an optimized pH 8.0 and extraction time 10.0 min. The adsorption process was fitted by the Langmuir model with a maximum adsorption capacity of 555.62 mg/g and 588.2 mg/g, respectively, for MB and MR. Under optimum conditions, the limit of detection (LOD) for MB was 0.7 μgL^-1 and 0.9 μgL^-1 for MR. Furthermore, the Co-Fe-LDH@UiO-66-NH₂ composite showed high efficiency for the removal of the analytes from environmental water samples.

Spray-Coating of Catalytically Active MOF-Polythiourea through Postsynthetic Polymerization

A UiO-66-NCS MOF was formed by postsynthetic modification of UiO-66-NH₂ . The UiO-66-NCS MOFs displays a circa 20-fold increase in activity against the chemical warfare agent simulant dimethyl-4-nitrophenyl phosphate (DMNP) compared to UiO-66-NH₂ , making it the most active MOF materials using a validated high-throughput screening. The -NCS functional groups provide reactive handles for postsynthetic polymerization of the MOFs into functional materials. These MOFs can be tethered to amine-terminated polypropylene polymers (Jeffamines) through a facile room-temperature synthesis with no byproducts. The MOFs are then crosslinked into a MOF-polythiourea (MOF-PTU) composite material, maintaining the catalytic properties of the MOF and the flexibility of the polymer. This MOF-PTU hybrid material was spray-coated onto Nyco textile fibers, displaying excellent adhesion to the fiber surface. The spray-coated fibers were screened for the degradation of DMNP and showed durable catalytic reactivity.

A Pyridyltriazol Functionalized Zirconium Metal-Organic Framework for Selective and Highly Efficient Adsorption of Palladium

This work reports the synthesis of pyridyltriazol-functionalized UiO-66 (UiO stands for University of Oslo), namely, UiO-66-Pyta, from UiO-66-NH₂ through three postsynthetic modification (PSM) steps. The good performance of the material derives from the observation that partial formylation (∼21% of -NHCHO groups) of H₂BDC-NH₂ by DMF, as persistent impurity, takes place during the synthesis of the UiO-66-NH₂. Thus, to enhance material performance, first, the as-synthesized UiO-66-NH₂ was deformylated to give pure UiO-66-NH₂. Subsequently, the pure UiO-66-NH₂ was converted to UiO-66-N₃ with a nearly complete conversion (∼95%). Finally, the azide-alkyne[3+2]-cycloaddition reaction of 2-ethynylpyridine with the UiO-66-N₃ gave the UiO-66-Pyta. The porous MOF was then applied for the solid-phase extraction of palladium ions from an aqueous medium. Affecting parameters on extraction efficiency of Pd(II) ions were also investigated and optimized. Interestingly, UiO-66-Pyta exhibited selective and superior adsorption capacity for Pd(II) with a maximum sorption capacity of 294.1 mg g^-1 at acidic pH (4.5). The limit of detection (LOD) was found to be 1.9 μg L^-1. The estimated intra- and interday precisions are 3.6 and 1.7%, respectively. Moreover, the adsorbent was regenerated and reused for five cycles without any significant change in the capacity and repeatability. The adsorption mechanism was described based on various techniques such as FT-IR, PXRD, SEM/EDS, ICP-AES, and XPS analyses as well as density functional theory (DFT) calculations. Notably, as a case study, the obtained UiO-66-Pyta after palladium adsorption, UiO-66-Pyta-Pd, was used as an efficient catalyst for the Suzuki-Miyaura cross-coupling reaction.

Poly(lauryl methacrylate)-Grafted Amino-Functionalized Zirconium-Terephthalate Metal-Organic Framework: Efficient Adsorbent for Extraction of Polycyclic Aromatic Hydrocarbons from Water Samples

In this study, a novel porous hybrid material, poly(lauryl methacrylate) polymer-grafted UiO-66-NH2 (UiO = University of Oslo), was synthesized for efficient extraction of polycyclic aromatic hydrocarbons (PAHs) from aqueous samples. The polymer end-tethered covalently to the MOF's surface was synthesized by surface-initiated atom transfer radical polymerization, revealing a distinct type of morphology. The adsorbent was characterized by scanning electron microscopy, energy-dispersive spectroscopy, transmission electron microscopy, powder X-ray diffraction, N2 adsorption-desorption analysis, Fourier transform infrared spectroscopy, and thermogravimetric analysis. The analyses were carried out by gas chromatography-mass spectrometry. Parameters including the type and volume of the eluent, the amount of the adsorbent, and adsorption and desorption times were investigated and optimized. Under optimal conditions, the limit of detection, intraday precision, and interday precision were in the range of 3-8 ng L-1, 1.4-3.1, and 4.1-6.5%, respectively. The procedure was used for analysis of PAHs from natural water samples.