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Zirconium-based metal-organic frameworks (Zr-MOFs) have been demonstrated as potent catalysts for the hydrolytic detoxification of organophosphorus nerve agents and their simulants. However, the practical implementation of these Zr-MOFs is limited by the poor processability of their powdered form and the necessity of water media buffered by a volatile liquid base in the catalytic reaction. Herein, we demonstrate the efficient solid-state hydrolysis of a nerve agent simulant (dimethyl-4-nitrophenyl phosphate, DMNP) catalyzed by Zr-MOF-based mixed matrix membranes. The mixed matrix membranes were fabricated by incorporating MOF-808 into the blending matrix of poly(vinylidene fluoride) (PVDF), poly(vinylpyrrolidone) (PVP), and imidazole (Im), in which MOF-808 provides highly active catalytic sites, the hydrophilic PVP helps to retain water for promoting the hydrolytic reaction, and Im serves as a base for catalytic site regeneration. Impressively, the mixed matrix membranes displayed excellent catalytic performance for the solid-state hydrolysis of DMNP under high humidity, representing a significant step toward the practical application of Zr-MOFs in chemical protective layers against nerve agents.

The development of proton conductors capable of working at above 100 °C is of great significance for proton exchange membrane electrolysis cells (PEMECs) and proton exchange membrane fuel cells (PEMFCs) but remains to be an enormous challenge to date. In this work, we demonstrate for the first time that the N-doped porous carbon derived from metal-organic frameworks (MOFs) with great superiority can be exploited for high-performing proton conductors at above 100 °C. Through the pyrolysis of ZIF-8, the N-doped porous carbon (ZIF-8-C) featuring high chemical resistance to Fenton's reagent was readily prepared and then served as a robust host to accommodate H 3 PO 4 molecules for proton transport. Upon impregnation with H 3 PO 4 , the resulting PA@ZIF-8-C exhibits low water swelling and high proton conduction of over 10 -2 S cm -1 at a temperature above 100 °C, which is superior to many reported proton conductors. This work provides a new approach for the design of high-performing proton conductors at above 100 °C.

Metal–organic framework (MOF) membranes with rich functionality and tunable pore system are promising for precise molecular separation; however, it remains a challenge to develop defect‐free high‐connectivity MOF membrane with high water stability owing to uncontrollable nucleation and growth rate during fabrication process. Herein, we report on a confined‐coordination induced intergrowth strategy to fabricate lattice‐defect‐free Zr‐MOF membrane towards precise molecular separation. The confined‐coordination space properties (size and shape) and environment (water or DMF) were regulated to slow down the coordination reaction rate via controlling the counter‐diffusion of MOF precursors (metal cluster and ligand), thereby inter‐growing MOF crystals into integrated membrane. The resulting Zr‐MOF membrane with angstrom‐sized lattice apertures exhibits excellent separation performance both for gas separation and water desalination process. It was achieved H2 permeance of ~1200 GPU and H2/CO2 selectivity of ~67; water permeance of ~8 L ⋅ m−2 ⋅ h−1 ⋅ bar−1 and MgCl2 rejection of ~95 %, which are one to two orders of magnitude higher than those of state‐of‐the‐art membranes. The molecular transport mechanism related to size‐sieving effect and transition energy barrier differential of molecules and ions was revealed by density functional theory calculations. Our work provides a facile approach and fundamental insights towards developing precise molecular sieving membranes. [ABSTRACT FROM AUTHOR]

Two rare earth metal–organic frameworks (MOFs), [Y2(PTC)2(H2O)2]·3H2O (Y-PTC) and [Eu2(PTC)2(H2O)5]·H2O (Eu-PTC) together with the solid solutions [Eu2xY2(1−x)(PTC)2(H2O)5]·H2O (EuxY1−x-PTC, x = 0.013–0.82), were synthesized hydrothermally, and characterized by microanalysis, IR spectroscopy, TG, powder, and single crystal X-ray diffraction techniques. Eu-PTC and Y-PTC showed different crystal structures; however, all solid solutions were isomorphic to Eu-PTC even at x = 0.013, leading to the IR spectra and TG plots of the solid solutions to be similar to those of Eu-PTC but distinct from those of Y-PTC. DFT calculations for the crystal lattice energy demonstrated that the procedure for the crystallizing nucleation of Eu-PTC occurred prior to that of Y-PTC in the reaction solution, leading to the all solid solutions being isomorphic to Eu-PTC. The solid emission spectra at ambient condition showed that Y-PTC emitted ligand-based phosphorescence at 433 nm with a quantum yield (QY) of 27.02%, while Eu-PTC and EuxY1−x-PTC (x = 0.013–0.82) emitted the characteristic luminescence of Eu3+ ions, and most solid solutions showed higher QYs than Eu-PTC; in particular, the QY of Eu0.195Y0.805-PTC was up to 29.48%, i.e., increased by 10% regarding Eu-PTC (19.86%). Interestingly, solid solutions with x = 0.013–0.395 showed excitation-wavelength-dependent luminescence, and such type of luminescence MOFs have promising applications including the areas of precise temperature, gas sensing and information encryption or anti-counterfeiting materials. [ABSTRACT FROM AUTHOR]

A multifunctional material, with two or more types of functionalities in a single material, might give new phenomena and novel applications. Metal–organic frameworks (MOFs) or porous coordination polymers (PCPs) can be utilized as a highly versatile and tunable platform for exploring multifunctional materials. In this study, an extra thermally stable indium–MOF (1) was synthesized via self-assembly of 1,1′-ethynebenzene-3,3′,5,5′-tetracarboxylic acid (H4EBTC) with an indium salt under solvothermal conditions. MOF 1 crystallizes in a tetragonal space group P4/mmm and shows a three-dimensional (3D) anionic framework with one-dimensional (1D) channels along the c-axis direction, and charge-balancing [(CH3)2NH2]+ cations together with lattice DMF and water molecules are accommodated in channels. This multifunctional MOF emits pure blue luminescence under ambient conditions, arising from the π* → π electron transition in EBTC4−, with CIE coordinates of (0.16, 0.07), and shows the highest quantum yield of 61.4% among indium–MOFs. Alternatively, 1 features fast proton conductivity with σ = 3.49 × 10−3 S cm−1 at 25 °C and 99% RH, attributed to the efficiently synergistic proton transfer in the H-bond networks constructed by [NH2(CH3)2]+ cations, lattice water molecules in channels and carboxylate groups in the framework. The notable level of performance of 1, combined with good hydrolytic and extra thermal stability, offers great opportunities for its future applications, and it may behave as a kind of promising multifunctional MOF material. [ABSTRACT FROM AUTHOR]

Two pairs of MOF-based hybrid enantiomorphs, [NH2(CH3)2]3[Pb2X3(BDC)2] (H2BDC = 1,4-benzenedicarboxylic acid, X = Br or I), have been synthesized using the solvothermal reaction and then manually separated, which are labeled as 1a/1b (X = Br) and 2a/2b (X = I). The isomorphic 1a and 2a crystallize in tetragonal space group P43212, and the isomorphic 1b and 2b in the enantiomorphic space group P41212. Twofold interpenetrated three-dimensional (3-D) networks were built from two sets of equivalent I1O2 type hybrid inorganic–organic frameworks in 1a/1b and 2a/2b. Each I1O2 type hybrid inorganic–organic framework constructs by the inorganic pentagonal bipyramid-shape PbX3O4 (X = Br or I) polyhedral chains along the c-axis, which are further connected though bridged BDC2− ligands in the directions perpendicular to the c-axis. Hybrids 1a/1b and 2a/2b have been characterized by elemental analysis (C, H and N elements), thermogravimetric and powder X-ray diffraction techniques, and UV-visible absorption spectroscopy in the solid state. These hybrids show dual emissions at ambient conditions, which arise from the π–π* electron transition within the aromatic rings in the BDC2− ligands and the electron transition in the inorganic polyhedral semiconducting chains, as well as thermochromic luminescence behavior from 10 to 300 K owing to two emission bands displaying different responses to the temperature change. [ABSTRACT FROM AUTHOR]

Proton-conducting materials show important technological applications as key components in energy conversion, electrochemical sensing and electrochromic devices; the exploration for new types of proton-conducting materials is crucial for the development of efficient electrochemical devices. In this study, we investigated the proton transport nature of an inorganic–organic hybrid crystal of open-framework cobalt phosphate, (C2N2H10)0.5CoPO4. The structure of the hybrid crystal consists of the [CoPO4]−∞ anionic framework, and the proton carriers, H2en2+ cations (en = ethylenediamine), are located in the pores to compensate the negative charges of the inorganic framework. The open-framework is thermally stable up to 653 K (380 °C) at least, and also shows superior water stability. The open-framework exhibits negligible conductance in an anhydrous environment even at 473 K; however, there is evident water-assisted proton conduction. The conductivity reaches 2.05 × 10−3 S cm−1 at 329 K and 98% RH. Such high proton conductivity can compete with numerous state-of-the-art MOFs/PCPs-based proton conductors, and this material has promising applications in diverse electrochemical devices. [ABSTRACT FROM AUTHOR]

A clathrate NH4Br@HKUST-1 has been prepared by means of soaking the metal–organic-framework, HKUST-1, in ammonium bromide saturated ethanol solution at ambient temperature. Both NH4Br@HKUST-1 and HKUST-1 show the same framework structure. The formula of the clathrate is approximately expressed as Cu3(BTC)2(NH4Br)1.15. The thermal stability of the metal–organic framework is not affected by incorporating ammonium bromide into its pores. The impedance spectra measurements were performed for both NH4Br@HKUST-1 and HKUST-1 in anhydrous and selected relative humidity environments, disclosing that the conductivity of NH4Br@HKUST-1 is enhanced by three/four orders of magnitude under the same conditions with respect to HKUST-1. This study provided an efficient strategy to achieve new high conductivity proton transport materials. [ABSTRACT FROM AUTHOR]

The lanthanide metal-organic frameworks (MOFs) [Ln 2 (EBTC) 1.5 (CH 3 OH) 4 ]·6H 2 O are isostructural to each other, where EBTC 4− =1,1′-ethynebenzene-3,3′,5,5′-tetracarboxylate; Ln 3+ =La 3+ , Eu 3+ and Tb 3+ ; and the corresponding MOF is abbreviated as Ln–EBTC . MOFs Eu–EBTC and Tb–EBTC emit intense red and green luminescence (visible by bare eyes), respectively. The molecular alloys of Eu x La 1− x – EBTC and Tb x La 1− x –EBTC have been successfully prepared by mixing Eu 3+ /Tb 3+ and La 3+ salts with the desired molar ratio in the starting material. Two series of Eu x La 1− x –EBTC and Tb x La 1− x –EBTC molecular alloys are isomorphic to the parent Ln–EBTC MOFs, while exhibit divergent La 3+ ion diluting effect, namely, with increasing the relative amount of La 3+ , the intensity of characteristic emission arising from Tb 3+ ion monotonely increases in Tb x La 1− x –EBTC molecular alloys, whereas that of Eu 3+ ion shows non-monotone decrease in Eu x La 1− x –EBTC molecular alloys. The possible origin is discussed for such a divergent behavior between Eu x La 1− x –EBTC and Tb x La 1− x –EBTC molecular alloys. [ABSTRACT FROM AUTHOR]

Zirconium-based metal-organic frameworks (Zr-MOFs) with periodic Lewis acidic nodes have demonstrated impressive catalytic activity in the hydrolysis of organophosphorus nerve agents. Nevertheless, the powdered form of Zr-MOFs and the necessity of a base-buffered aqueous solution during the catalytic reaction pose significant challenges to their practical utilization. In this study, we demonstrate the efficient hydrolysis of an organophosphorus nerve agent simulant, dimethyl-4-nitrophenyl phosphate (DMNP), in both pure water and the solid phase under high humidity conditions, catalyzed by a membrane material. This material, denoted as Im@MOF-808/PVDF, was synthesized through the integration of MOF-808 particles onto PVDF membrane fibers, with imidazole (Im) molecular bases incorporated into the pores of MOF-808. Our findings emphasize the excellent flexibility and processability inherent in Im@MOF-808/PVDF. More notably, it exhibits exceptional catalytic performance in the hydrolysis of DMNP in pure water. Additionally, it demonstrates fair catalytic activity for solid-phase DMNP hydrolysis under high humidity conditions. These features position Im@MOF-808/PVDF as one of the most promising protective materials, showcasing substantial practical applicability. [Display omitted] • Im@MOF-808/PVDF was prepared by integrating MOF-808 particles onto PVDF membrane and adsorbing imidazole molecules into MOF-808 pores. • Im@MOF-808/PVDF exhibited much high catalytic activity toward the hydrolysis of nerve agent simulants in pure water. • Im@MOF-808 displayed considerable catalytic acitivity for solid-phase hydrolysis of nerve agent simulants. [ABSTRACT FROM AUTHOR]

• Complete reduction of CuII to highly dispersive CuI was achieved on MIL-101. • Both cobalt doping and keeping metal sites at the interior of MIL-101 facilitate the dispersion and reduction. • CuCoM-DS adsorbents show superior performances in C 2 H 4 /C 2 H 6 separation to MIL-101, CuCoM-WI, CuCoM-SG and CuM-DS. Adsorbents based on CuI for π-complexative separation of C 2 H 4 /C 2 H 6 have attracted widespread interests. However, they are still confronting some challenges, for example, (i) a low separation efficiency, resulted from the ineffective reduction of CuII to CuI along with aggregation, and (ii) poor stability due to the oxidation of CuI to inactive CuII. In this study, active Cu and auxiliary Co species are simultaneously encapsulated within the nanopores of MIL-101 using a double-solvent (DS) method to obtain CuCoM-DS. The Cu species at the interior of MIL-101 are homogeneously dispersed and can be completely reduced to CuI without any structural damage to MIL-101. The resulting CuCoM-DS exhibits a superior performance in C 2 H 4 /C 2 H 6 separation not only to the pristine MIL-101, but to the counterpart samples of single Cu and/or Cu/Co at the exterior of MIL-101. The best sample of 1.5CuCoM-DS adsorbent is capable to adsorb 50.5 mL·g−1 of C 2 H 4 , and the C 2 H 4 /C 2 H 6 selectivity is 2.6 at 100 kPa. Both C 2 H 4 uptake and C 2 H 4 /C 2 H 6 selectivity are higher than those reference samples. Moreover, 1.5CuCoM-DS preserves over 90% of fresh C 2 H 4 uptake after the exposure to atmospheric air for 12 days. This study provides new design ideas for confining bimetallic sites in MOFs for broad applications. [ABSTRACT FROM AUTHOR]

The development of a highly efficient sensor capable of detecting formic acid is crucial for monitoring air quality and determining the leakage because of the strong corrosivity and pungency. In this work, we present the superiority of a proton conductive metal-organic framework (MOF) thin film as a sensing material for highly efficient detection of formic acid at room temperature. Specifically, MOF-801, a zirconium-based MOF, exhibits exceptional chemical stability and inherent proton conduction, along with a significant surface area and high porosity. Through the solvothermal synthetic method, highly uniform and densely packed thin films of MOF-801 are successfully fabricated on glass substrates. The resulting sensor, based on MOF-801 thin films, displays exceptional sensitivity, selectivity, and durability for detecting formic acid at room temperature, outperforming both other MOFs based sensors and the traditional metal-oxide-based sensors that operate at high temperatures. [Display omitted] • The dense packing and uniform crystalline thin films of proton conductive MOF-801 are successfully grown on glass substrate through solvothermal synthetic approach. • The MOF-801 thin film sensor displays high sensitivity, good selectivity and remarkable durability for formic acid detection at room temperature. [ABSTRACT FROM AUTHOR]

A three-dimensional open-framework aluminophosphate, (NH 4 ) 2 Al 4 (PO 4 ) 4 (HPO 4 )·H 2 O ( 1 ), shows two types of eight-membered polyhedral ring channels. The lattice water molecules occupy within the channel with (HO)PO 3 tetrahedra (channel-I), whilst the ammonium ions reside in another type of channel (channel-II). This aluminophosphate shows superior stability to water and NaOH aqueous solution, but unstable to H 2 SO 4 aqueous solution. The proton conductance of 1 has been investigated under anhydrous condition and various relative humidity, indicating rather low conductivity under anhydrous condition even at elevated temperature (σ dc = 9.05 × 10 − 13 S cm −1 at 343 K and 4.25 × 10 −10 S cm −1 even at 473 K), and this situation demonstrates that both the ammonium ions and the protons in (HO)PO 3 tetrahedra have quite low mobility. The conductivity of 1 reaches to 4.0 × 10 −5 S cm −1 at 299 K, 2.57 × 10 −4 S cm −1 at 343 K under 99%RH, respectively. The greatly enhancement of proton conductivity at 99%RH is due to the formation of H-bond between H 2 O molecules and (HO)PO 3 tetrahedra in the channel-I to assist proton hopping process, while the ammonium ions show negligible contribution to enhancement of proton conductivity. [ABSTRACT FROM AUTHOR]

A bimetallic metal–organic framework (MOF) with the formula [Zn 3 btc 2 {Cr 3 O(isonic) 6 (H 2 O) 2 (OH)}]·(DMF) 15.5 (H 2 O) 8 (H 3 btc=1,3,5-benzenetricarboxylic acid; isonic=isonicotinicate) shows a pillar-layered structure. The monolayer consists of hexagon-like rings formed by the [Zn(isonic) 2 (btc) 2 ] tetrahedral and the consecutive monolayers are pillared by trigonal–prismatic clusters of [Cr 3 O(isonic) 6 (H 2 O) 2 (OH)]through the remaining binding sites of the Zn 2+ ions. DMF and water molecules are confined in the cages and channels. TGA indicates that the lattice DMF and water molecules begin to be released at temperatures above 363 K. Dielectric measurements were carried out in the range of 173–363 K and 1–10 7 Hz for three successive thermal cycles. The dielectric spectroscopy obtained in the first thermal cycle was different from that observed in the next two thermal cycles, while the dielectric spectra in the last two thermal cycles were almost identical. The dielectric nature of this MOF is discussed in detail for each thermal cycle. Since MOFs are unique host–guest systems in which the structure of the host framework is designable and the guests are exchangeable, it is no doubt those MOFs are materials with a variety of dielectric natures. This study gives a fresh impetus to achieve MOFs–based dielectric materials. [ABSTRACT FROM AUTHOR]

A series of rare earth solid solutions, Tb 1- x Y x -PTC with pyridine-2, 4, 6-tricarboxylic acid (H 3 PTC), have been prepared using a hydrothermal synthesis method and characterized by single crystal and powder X-ray diffraction, IR spectroscopy, and thermogravimetric analysis techniques etc. Tb 1- x Y x -PTC are isomorphous with 1D zigzag metal-oxide chains and 2D coordination polyhedral layers, which are further interlinked into 3D framework by the connection of PTC3− ligands. The photoluminescent behaviors of the solid solutions Tb 1- x Y x -PTC were carefully studied. The QY of Tb 1- x Y x -PTC with appropriate amount of Y3+ ion is obviously enhanced due to reducing dipole–dipole and quadrupole–quadrupole interaction between emitters of Tb3+ ions. This study demonstrates that the formation of solid solutions by introducing optically inactive ions is an efficient strategy to get improved photoluminescent materials. In Tb 1- x Y x -PTC, there is an intrinsic "trade-off" effect among reducing concentration quenching and luminescence emitting centers reducing. [Display omitted] • A series of rare earth solid solutions, Tb 1- x Y x -PTC, were successfully synthesized. • The solid solutions Tb 1- x Y x -PTC are isomorphic to the parent Tb-PTC MOF. • The solid solutions Tb 1- x Y x -PTC have longer millisecond-grade luminescence lifetimes and higher quantum yields. • The QY of Tb 1- x Y x -PTC with appropriate amount of Y3+ ion is obviously enhanced. [ABSTRACT FROM AUTHOR]

The oxygen evolution reaction (OER) electrocatalyst is highly desirable as it plays an important role in many energy conversion technologies by effectively reducing the OER process overpotential. Herein, the morphology, crystal structure and more importantly, the OER electrochemical activity of Scandium-doped MIL-101(Fe) were investigated. It was found that the competitive nucleation as well as the difference in the oxytropism between Sc3+ and Fe3+ ions, which lead to the crystalline structure change and consequently the morphology evolved from quadrangular star-shaped bipyramid to hexagonal bipyramids. Moreover, the OER electrocatalysis performance was improved significantly when incorporation Sc3+ ion into the MIL-101(Fe) host body. The X-ray photoelectron spectroscopy (XPS) analysis demonstrated that the strong bimetal interaction between Fe3+ and Sc3+ ions, leading to well-modified Fe3+ electronic structure. It yielded optimal hydroxyl adsorption energy on Fe3+ and thus facilitated the process of O 2 evolution. Such Sc3+ ion doping strategy to modulate the OER performance was also extendable to other Metal-organic frameworks (MOFs) structures. It demonstrates a better OER activity with a low overpotential of 300 ​mV at 10.0 ​mA ​cm−2 and Tafel slope of 125 ​mV dec−1 for Sc-CoBDC-3, which provides great potential for fabricating optimal OER MOFs. [Display omitted] • Scandium-doped MIL-101(Fe) microcrystals with morphology evolution from quadrangular star-shaped bipyramid to hexagonal bipyramids were obtained. • The oxygen evolution reaction (OER) electrocatalysis performance of MIL-101(Fe) was improved significantly by incorporation proper amount Sc3+ ion. • The Sc3+ ion doping strategy to modulate the OER performance was extendable to other Metal-organic frameworks (MOFs) structures. [ABSTRACT FROM AUTHOR]

A series of rare earth metal organic frameworks (MOFs), including Tb-PTC and solid solutions Tb x Eu y Y 1- x - y -PTC with pyridine-2, 4, 6-tricarboxylic acid (H 3 PTC), have been prepared using a hydrothermal synthesis method and characterized by single crystal and powder X-ray diffraction, IR spectroscopy, elemental analysis and thermogravimetric analysis techniques etc. Tb-PTC and Tb x Eu y Y 1- x - y -PTC are isomorphous with 1D zigzag metal-oxide chains, which are further interlinked into 3D framework by the connection of PTC3− ligands. The solid solutions, Tb x Eu y Y 1- x - y -PTC, are single-phase white-light emitters with higher quantum yields (47.6–69.6%) and longer millisecond-grade luminescence lifetimes. This study unveils the possibility to achieve high quantum yield white light emitter by rational design of rare earth MOF solid solutions. A series of rare earth metal organic framework solid solutions, Tb x Eu y Y 1- x - y -PTC, emit high quantum yield white light. [Display omitted] • A series of solid solutions, Tb x Eu y Y 1- x - y -PTC, were successfully synthesized. • The solid solutions are single-phase white-light emitters with high quantum yields. • The solid solutions have long millisecond-grade luminescence lifetimes. [ABSTRACT FROM AUTHOR]