Energetic MOF-derived FeC nanoparticles encased in N,S-codoped mesoporous pod-like carbon nanotubes for efficient oxygen reduction reaction.

The rational design of advanced oxygen reduction reaction (ORR) catalysts is essential to improve the performance of energy conversion devices. However, it remains a huge challenge to construct hierarchical micro-/meso-/macroporous nanostructures, especially mesoporous transport channels in catalysts, to enhance catalytic capability. Herein, motivated by the characteristics of energetic metal-organic frameworks (EMOFs) that produce an abundance of gases during high-temperature pyrolysis, we prepared a unique tetrazine-based EMOF-derived electrocatalyst (denoted as FeC@NSC-900) consisting of highly dispersed FeC nanoparticles and N,S-codoped mesoporous carbon nanotubes.

The Effects of Ligands with Different Electron Donation on the Nitrogen Reduction Performance of Constructed Co-MOFs: NH or NH?

Four cobalt-based metal-organic frameworks (Co-MOFs) based on different ligands with varying electron-donating properties (dpt = 2,5-di(pyridin-4-yl)-1,3,4-thiadiazole, NH₂bdc = 5-aminoisophthalic acid, OHbdc = 5-hydroxyisophthalic acid, H₂tdc = thiophene-2,5-dicarboxylic acid, and hfipbb = 4,4'-(hexafluoropropane-2,2-diyl)bisbenzoic acid) are synthesized. Among them, Co-dpt-NH₂bdc demonstrates the highest nitrogen reduction reaction activity, achieving an ammonia (NH) yield of 68.61 µg·h⁻¹·mg⁻¹ and Faraday efficiency (FE) of 6.

Bioinspired Molecular Scalpel for Two-Dimensional Metal-Organic Nanosheet: Design Strategies and Recent Progress.

Ultrathin two-dimensional (2D) metal-organic nanosheets (MONs) have attracted continued attention in the field of advanced functional materials. Their nanoscale thickness, high surface-to-volume ratio, and abundant accessible active sites, are superior advantages compared with their 3D bulk counterparts. Bioinspired molecular scalpel strategy is a promising method for the creation of 2D MONs, and may solve the current shortcomings of MONs synthesis.

Small-size and well-dispersed Fe nanoparticles embedded in carbon rods for efficient oxygen reduction reaction.

The preparation of ultra-small and well-dispersed metal nanoparticles (NPs) is of great importance for promoting oxygen reduction. Here, a metal (Fe and Zn) NP (7 nm) based catalyst derived from a Zn-based metal-organic framework was obtained by a vapor adsorption strategy, demonstrating a high half-wave potential (0.868 V) and power density (196 mW cm).

Customized Synthesis of MOF Nanoplates via Molecular Scalpel Strategy for Efficient Oxygen Reduction in Zn-Air Batteries.

The production of metal-organic framework (MOF) nanoplates with well-defined geometric morphology is remarkable for expanding their applications. Herein, the cobalt-based MOF nanoplates with hexagonal channels from a layer-pillared MOF are accomplished, via a molecular scalpel strategy, utilizing monodentate pyridine to replace the bidentate 4,4'-bipyridine. The morphology can be modified from nanorods to nanoplates with controllable thickness tuned by the amounts of pyridine.

A solvent-responsive terbium-organic framework for photocatalytic CO reduction.

A Tb-MOF with a 5,5,6-c 3-nodal net, {[Tb(DTDA)·2HO]·DMF·8HO} (AQNU-4), has been synthesized (DTDA = 2',5'-diethoxy-[1,1':4',1''-terphenyl]-4,4''-dicarboxylic acid). AQNU-4 contains a 1-periodic secondary building unit (rod SBU) and has an unusual topological type with the point symbol {3·4·6·7·8}{3·4·5·6}{3·4·5·6}. Efficient light harvesting and electron-hole separation make AQNU-4 an effective photocatalyst for use in the CO reduction reaction (CORR).

Regulation of Chirality in Metal-Organic Frameworks (MOFs) Based on Achiral Precursors through Substituent Modification.

The generation and regulation of chirality are closely related to the origin of life. Using achiral precursors to spontaneously build chiral MOFs remains a major challenge. Here, a method to synthesize chiral MOFs from achiral precursors by utilizing chiral fragments was achieved.

Interfacing MnO and FeCo alloy inside N-doped carbon hierarchical porous nanospheres derived from metal-organic framework to boost high-performance oxygen reduction for Zn-air batteries.

Efficient and strong non-precious metal catalysts are urgently needed for the oxygen reduction reaction (ORR). Here, a facile hydrothermal-pyrolysis process was implemented to engineer CoFe-MnO heterointerfaces encapsulated in N-doped carbon (CFM-NC) nanospheres with a metal-organic framework (MOF) as the precursor. Due to heterointerfaces and hierarchical porosity, CFM-NC-800 exhibited superior ORR activity (half-wave potential of 0.

A stable Cd-MOF as a dual-responsive luminescent biosensor for the determination of urinary diphenyl phosphate and hippuric acid as biomarkers for human triphenyl phosphate and toluene poisoning.

Rapid and accurate determination of biomarkers of human poisoning in real urine is of great significance for the assessment of health status. Herein, a luminescent urea-functionalized metal-organic framework (MOF), {[Cd(L)(bpbix)]·(solv)} (1) (HL = 5,5'-(((naphthalene-1,5-diylbis(azanediyl))bis(carbonyl))bis(azanediyl))diisophthalic acid; bpbix = 4,4'-bis((1-imidazol-1-yl)methyl)biphenyl), has been successfully synthesized, and exhibits good stability in aqueous solutions in the normal urinary pH range and real urine. Complex 1 can serve as a dual-responsive luminescent biosensor for the detection of diphenyl phosphate (DPP) and hippuric acid (HA) as biomarkers of flame retardant triphenyl phosphate and toluene poisoning, and shows the advantages of high sensitivity, rapid response, good anti-interference capability, and reversibility.

Stable Cd Metal-Organic Framework as a Multiresponsive Luminescent Biosensor for Rapid, Accurate, and Recyclable Detection of Hippuric Acid, Nucleoside Phosphates, and Fe in Urine and Serum.

Detecting biomarkers associated with diseases has significant meaning for early prevention, diagnosis, and treatment of diseases. The development of luminescent biosensors for rapid and accurate detection in real urine and serum is urgently desired for human health monitoring. Herein, a luminescent cadmium metal-organic framework, {[Cd(L)(bpbix)]·(solv)} (), was successfully prepared by using a urea-functionalized dicarboxylate ligand, 5-(3-(pyridin-4-yl)ureido)isophthalic acid (HL), 4,4'-bis((1-imidazol-1-yl)methyl)biphenyl (bpbix), and the Cd ion.

From Hydrogen Bond to van der Waals Force: Molecular Scalpel Strategy to Exfoliate a Two-Dimensional Metal-Organic Nanosheet.

The facile exfoliation of a two-dimensional metal-organic nanosheet of {[Co(HL)(HO)(Py)]·/HO·DMF} [; HL = 5-(1-pyrazol-4-yl)isophthalic acid and Py = pyridine] was achieved, via a molecular scalpel strategy, by weakening intermolecular forces between adjacent layers. The resulting (KB = Ketjen black) shows an increased oxygen evolution reaction (OER) performance with an overpotential of 370 mV at a current density of 10 mA cm and a Tafel slope of 58 mV dec. This work sheds light on the structure-morphology-reactivity relationship of such materials in OER.

Response to the Temperature and Solvent Stimulation of MOF Material in a Single-Crystal to Single-Crystal Manner.

Under solvothermal conditions, a three-dimensional mononuclear crystal AQNU-1, {[Co(HL)(DPD)(HO)]·2DMA} (HL = 5-(bis(4-carboxybenzyl)amino)isophthalic acid, DPD = 4,4'-(2,5-diethoxy-1,4-phenylene)dipyridine) has been synthesized. The transformations of AQNU-1 to binuclear {[Co(L)(DPD)(HO)]·DMA·HO} (AQNU-2) and pentanuclear {[Co(L)(DPD)(OH)]·2HO} (AQNU-3) were realized by double stimulation of temperature and solvent, which were accomplished by single-crystal to single-crystal (SC-SC) reaction.

MOF-derived CoNi,CoO,NiO@N-C bifunctional oxygen electrocatalysts for liquid and all-solid-state Zn-air batteries.

Metal-organic framework (MOF)-derived carbon composites with embedded metal alloy/metal oxides have attracted much attention due to their low-cost and excellent electrochemical reactivity. However, the drawback of this concept is the severe carbon evaporation during their synthesis, resulting in a reduction of active sites and catalytic durability. To solve this problem, this study proposes the possibility of using Ketjen black (KB) to replenish the carbon content.

A Water-Stable Tb-MOF As a Rapid, Accurate, and Highly Sensitive Ratiometric Luminescent Sensor for the Discriminative Sensing of Antibiotics and DO in HO.

The design and development of self-calibrating ratiometric luminescent sensors for the fast, accurate, and sensitive discrimination and determination of pollutants in wastewater is highly desirable for public and environmental health. Herein, a 3D porous Tb(III)-based metal-organic framework (MOF), {[Tb(HL)(HO)]·(solv)} (), was facilely synthesized using a urea-functionalized tetracarboxylate ligand, 5,5'-(((1,4-phenylenebis(azanediyl))bis(carbonyl))bis(azanediyl))diisophthalic acid (HL). The activated framework showed a good water stability in both aqueous solutions at a wide pH range of 2-14 and simulated antibiotic wastewaters.

The difference in the CO adsorption capacities of different functionalized pillar-layered metal-organic frameworks (MOFs).

The excessive use of fossil energy has caused the CO2 concentration in the atmosphere to increase year by year. MOFs are ideal CO2 adsorbents that can be used in CO2 capture due to their excellent characteristics. Studies of the structure-activity relationship between the small structural differences in MOFs and the CO2 adsorption capacities are helpful for the development of efficient MOF-based CO2 adsorbents.

Mixed matrix membranes containing fluorescent coordination polymers for detecting CrO with high sensitivity, stability and recyclability.

Three coordination polymers (CPs) were synthesized by using CdII, fluorescent 9,10-di(4-pyridyl)anthracene (dpa), and cyclohexane-1,4-dicarboxylic acid (H2cda), and they are [Cd2(dpa)2(cda)Cl2]n (1), [Cd(dpa)2(cda)]n (2) and [Cd(dpa)(cda)(H2O)]n (3). Both 1 and 2 are fluorescent and contain nonporous layers. 3 is an isomer of 2 and contains a porous diamondoid network.

Molecular engineering in a family of pillared-layered metal-organic frameworks for tuning gas adsorption behavior.

In this work, inspired by a water-assisted three-dimensional supramolecular structure 1, we use a mixed-ligand strategy to form a 3D pillared-layered matrix by the introduction of linear ligands to compete against the water molecules. The resulting analogue microporous MOFs of 2-H, 2-F and 2-N, decorated with different functional groups, similarly show the CO2 uptake. Thanks to the negligible N2 adsorption capacity, enhanced selective adsorption towards CO2 is achieved in compound 2-N.

A Europium-based MOF Fluorescent Probe for Efficiently Detecting Malachite Green and Uric Acid.

Lanthanide (such as Tb and Eu) metal-organic frameworks (MOFs) have been widely used in fluorescent probes because of their multiple coordination modes and brilliant fluorescence characteristic. Many lanthanide MOFs were applied in detecting metal ions, inorganic anions, and small molecules. However, it's rarely reported that Ln-MOF was devoted to detecting malachite green (MG) and uric acid (UA).

Improving the Stability and Visualizing the Structural Transformation of the Stimuli-Responsive Metal-Organic Frameworks (MOFs).

New metal-organic frameworks (MOFs) based on flexible tetra-carboxylate ligands and Cu(II) are designed to gain stimuli-responsive materials. Unstable MOFs can be more stable with unabated flexibility by replacing coordinated solvent molecules with auxiliary N-based ligands. Two of them are intensively studied by in situ single-crystal X-ray diffraction (SCXRD) analysis and the unit cell parameters during transformations have been observed in detail.

Tetrazole-based porous metal-organic frameworks for selective CO adsorption and isomerization studies.

Tetrazole-based molecules have numerous bridging coordination modes which afford great synthetic possibilities for the preparation of porous metal-tetrazolate architectures for many applications, such as carbon capture. We reported here three tetrazole-based MOFs: 1, {[Cu(ttz)Cl(HO)]·11Cl} (Httz = N,N,N-tris(4-(1H-tetrazol-5-yl)phenyl)-1,3,5-triazine-2,4,6-triamine), contains highly positively charged Cu clusters and the largest mesopores (32 Å) among the reported MOFs based on a tri-topic tetrazole ligand. 2 and 3 are two MOF isomers built by using Cu and 2-(1H-tetrazol-5-yl)pyrimidine.

Three Anionic Indium-Organic Frameworks for Highly Efficient and Selective Dye Adsorption, Lanthanide Adsorption, and Luminescence Regulation.

Through solvothermal reaction of InCl and tetracarboxylate ligands with different substituent groups on diphenyl ethers, three new anionic indium-organic frameworks have been successfully prepared. They are {[(CH)NH]In(G-1)(HO)}·9DMF (1), {[(CH)NH]In(G-2)}·15DMF (2), and {[(CH)NH]In(G-3)}·16DMF (3) {DMF = N, N'-dimethylformamide; H(G-1) = 5',5″″-oxybis(2'-methoxy[1,1':3',1″-terphenyl]-4,4″-dicarboxylic acid); H(G-2) = 5',5″″-oxybis(2'-amino[1,1':3',1″-terphenyl]-4,4″-dicarboxylic acid); H(G-3) = 5',5″″-oxybis([1,1':3',1″-terphenyl]-4,4″-dicarboxylic acid)}. Compounds 1-3 can be simplified as unimodal 4-connected frameworks with different topological types: lon, cag, and dia, respectively.

Effective adsorption of Congo red by a MOF-based magnetic material.

Metal-organic frameworks (MOFs) are an exciting class of porous crystallized materials, which have attracted great interest in sustainable energy and environmental remediation. Magnetite (Fe3O4) is one of the best-known magnetic materials and has been extensively studied with respect to properties involving high saturation magnetization, biocompatibility and low toxicity. The combination of MOFs and Fe3O4 has shown its potential applications in drug delivery, catalysis and wastewater treatment.

An excellent example illustrating the fluorescence sensing property of cobalt-organic frameworks.

A novel luminescent cobalt-organic framework was assembled and employed as a chemosensor for the detection of metal ions via fluorescence enhancement and quenching. The sensing mechanism was based on the exposed pyridyl and carboxyl functional sites in the MOF structure, which interacted with metal ions via Lewis acid-base interactions and electrostatic interactions.

Two MOFs as dual-responsive photoluminescence sensors for metal and inorganic ion detection.

Two metal-organic frameworks (MOFs), [Zn(BIPA)(tfbdc)]n (1) and {[Cd(BIPA)(tfbdc)(H2O)]·DMF}n (2), were hydrothermally synthesized using the self-assembly of the "V-shape" BIPA ligand (bis(4-(1H-imidazol-1-yl)phenyl)amine) and the H2tfbdc ligand (2,3,5,6-tetrafluorobenzene-1,4-dicarboxylic acid) with Zn/Cd metal salts. 1 is a 2D hcb framework and 2 is a 2D sql network. Their applications in detecting metal and inorganic ions were also explored.