Mixed matrix membranes (MMMs) incorporating metal-organic frameworks (MOFs) hold great promise for energy-efficient carbon capture, yet are fundamentally limited by interfacial defects and the ubiquitous permeability-selectivity trade-off. Herein, we propose a nanoconfinement strategy via in-situ interfacial polymerization to synthesize ultrathin MOF nanosheets and thus integrate them into PIM-1 matrix, a typical representative of polymers of intrinsic microporosity (PIMs), crafting a defect-free membrane. The meticulously designed MOFs, featuring synergistic amino functionalities and unsaturated Cu2+ sites, endows the optimal membrane (PIM-MOF-1%) with exceptional CO2 affinity and tailored molecular-sieving pathways. Consequently, it achieves a remarkable combination of high CO2 permeability (5186 barrer) and CO2/N2 selectivity (41), surpassing the 2019 Robeson upper bound. Impressively, this superiority persists under harsh conditionsexceeding the 2008 Robeson upper bound at 80 degrees C and sustaining high performance at 15 bar. Moreover, the membrane demonstrates exceptional long-term durability, preserving excellent separation performance, with CO2 permeability of 3078 barrer and CO2/N2 selectivity of 46, even after 180 days of aging. Our strategy aligns nanoconfined MOF architectures with polymer matrix, thereby resolving critical challenges in carbon capture through the simultaneous enhancement of separation efficiency and durability.

The environmental hazards posed by antibiotics underscore the critical need for rapid and effective monitoring methods. Their presence across diverse environmental matrices also creates varied detection conditions and operational challenges. Here, a stable and tunable dual-emission metal-organic framework (MOF), Eu@UiO-67, was developed for the ratiometric fluorescence sensing of antibiotics. Constructed via a rational mixed-ligand strategy—where 4,4′-biphenyl-dicarboxylic acid (H2L-BPH) acts as an efficient antenna for sensitizing Eu3+ and 2,2′-bipyridine-5,5′-dicarboxylate acid (H2L-BPY) provides a stable blue reference emission—followed by post-introduction of Eu3+ functionalization, the sensor integrates well-separated blue (425 nm) and red (614 nm) emissions. This design enables excitation-wavelength-tunable dual-channel emission and reliable self-calibration. Eu@UiO-67 exhibits distinct, antibiotic-specific response patterns: both oxytetracycline (OTC) and tetracycline (TCY) induce a dual-quenching effect, whereas moxifloxacin (MXF) elicits unique ratiometric enhancement via a combined FRET/PET mechanism. It demonstrates excellent stability over a wide pH range of 1 to 11 and in various alcohol/water solvents. Interestingly, by tuning the alcohol–water solvent ratio, both the ratiometric sensing metrics (sensitivity and dynamic range) and the fluorescence colorimetric response can be flexibly modulated, offering customizable detection with tailored chromatic output. For MXF, the probe exhibits a low detection limit of 0.065 μM. Segmented measurements in various solvent systems enable signal responses across the full concentration range of 0–200 μM, accompanied by a visible colorimetric transition. The sensor shows high selectivity and reproducibility under diverse circumstances. This work presents a versatile, stable, and performance-tunable sensing platform with significant potential for on-site antibiotic monitoring.

The detection of amine compounds, including amino acid identification, is pivotal for advancing biological disease surveillance and for evaluating food safety and environmental contamination. Here, the novel photoluminescence(PL) sensor of a ruthenium-based metal-organic framework for aliphatic amines and arginine is reported, with naked-eye distinguishable color changes and ultrahigh sensitivity. A dual-emission UiO-67-Ru metal-organic framework (MOF) engineered through mix-and-match integration of [Ru(bpy)(3)](2 +) into the UiO-67-bpy framework, which generates two different PL groups under a single backbone. At a low 5 % Ru-doping level, it was found that the UiO-67-Ru displays the most optimized photoluminescence while preserving framework integrity and microscopic morphology. The sensor exhibits dual emission at 380 nm (from the MOF backbone) and 665 nm (from the Ru center), enabling ratiometric detection of aliphatic amines. Specifically, ultrasensitive arginine (Arg) detection was achieved with a limit of detection (LOD) of 0.072 mu M, a linear range of 0-10 mu M, and a distinct color transition. Selectivity profiling against thirteen nitrogenous species (e.g., lysine, dopamine) shows UiO-67-Ru favors Arg over n-pentylamine by > 5-fold, a bias traced to Lewis acid-base pairing between aliphatic amines and electron-deficient bipyridine linkers. DFT reveals that amines selectively quench the 665 nm emission of [Ru(bpy)(3)](2)(+) via weak C-HN hydrogen bonds; this adduct narrows the MLCT gap and triggers PET, extinguishing red PL. Finally, the sensor maintains greater than 90 % PL intensity after 7-day storage and three sensing cycles, showcasing its practical applicability in complex environments.

Mixed matrix membranes (MMMs) are crucial for CO2 separation and offer a potential solution to overcome conventional gas separation. Nevertheless, MMMs face challenges due to interfacial defects in membranes, which results in poor gas separation performance. In this study, gamma-cyclodextrin (gamma-CD) based MMMs were synthesized via a simple solution casting method. gamma-CD could be molecularly dispersed in Matrimid matrix up to 3 wt% loading without defects at the interfaces in membranes. ATR-FTIR results showed that gamma-CD based MMMs have significant peak with loading increases. Leveraging the high CO2 solubility and high porosity of gamma-CD, Matrimid/gamma-CD based membranes exhibit improved CO2/CH4 selectivity. Especially, the CO2 permeability of Matrimid-3%-CD membrane increased by 40 % (from 13.35 to 18.71 Barrer) and CO2/CH4 increased by 99 % (from 36.08 to 71.96), respectively compared to pristine Matrimid membrane. This demonstrates that the incorporation of gamma-CD in Matrimid membrane significantly improves both permeability and selectivity. The Matrimid-gamma-CD membrane also demonstrated superior long-term operation stability after aging 593 days. Thus, this study lays the foundation for the development of gamma-CD-based membranes with high CO2/CH4 selectivity, providing potential pathways for CO2 separation processes in CO2/CH4 separation.

Highly permeable and selective biomimetic membranes that can feel and recognize valuable ion species have attracted enthusiastic interest due to their analogous behavior with biological ion channels and potential applications in rigorous ion sieving. However, designing and developing single-species selective membranes that can isolate monovalent cations such as K+/Na+ remains a tremendous challenge due to the sub-nanometer ion size, as well as the angstrom-sized difference. Considering the non-homogeneous heterostructure of KcsA channels and -COOH groups generally showing lower K+ affinity, we propose the 1D MOF (rich in -COOH groups)-in-2D COF concept, aiming to enhance K+/Na+ separation through strategic construction of heterogeneous ion transport channels, therefore narrowing the pore size of pristine COF membrane, and weakening the K+-channel wall interactions. Concretely, by interlocking and in situ immobilized growth, the pristine COF membrane is capable of capturing MOF ligands and metal ions in sequence to form 1D MOF-in-2D COF hetero-structured composite membranes. Benefiting from the molecular-level interlinked hybridization of covalent and metal organic hetero-frameworks induced by the coordination interaction between the -NH groups in COFs and the Cu centers from MOFs, the composite membrane enables rapid diffusion of K+ in confined heterogeneous channels, thus leading to unprecedented cation sieving performance with K+/Na+ selectivity approaching 102 and K+/Mg2+ selectivity exceeding 103. This membrane design concept exploits a viable avenue for developing single-species selective biomimetic membranes to achieve ultrahigh separation performance.

Despite enormous research efforts in recent years, polymer-metal-organic framework (polyMOF) development still faces several drawbacks, such as the substantial decrease in surface area, poor crystallinity, and monophyletic chemical structure of polyMOFs. Herein, we overcome the constraints of the coordination mode of conventional polyMOFs and report a bridging coligand strategy to prepare new types of polyMOFs, where the MOFs featuring accessible CuII sites are compelled to orientally regrow within the confined channels of semirigid PIM-1 in dimethyl sulfoxide. Coordination-substitution characteristics and solvent-modulated synthesis enable the Cu centers in MOFs to coordinate with the N atoms from PIM-1 by bridging coligand mode. The reduced particle size, enhanced ultramicroporosity, preferential orientation, and superior filler-matrix compatibility endow the polyMOF-based mixed matrix membrane with excellent CO2 separation performance, with a CO2 permeability of 4669 Barrer, and with a CO2/N2 selectivity of ∼30. This polyMOF design concept exploits a viable avenue for developing more inorganic-organic hybrid materials.

Copper ions are a significant concern to people's health and wine quality. By adopting a "one-pot" approach, tetra(4-carboxyphenyl)porphyrin (TCPP) molecules were integrated into UiO-66-NH2 metal-organic frameworks, forming TCPP@UiO-66-NH2 dual-emission fluorescence sensing platform towards copper ions. The blue fluorescence of UiO-66-NH2 at 466 nm was deemed an internal reference signal; thus, the built-in corrections in the complex were effectively achieved. The red emission fluorescence of TCPP at 654 nm was quenched by Cu2+, resulting in a reliable signal and noticeable color changes. A quick and sensitive ratio fluorescence sensor was constructed with the signal contrast mechanism. This sensor enabled trace detection of Cu2+ within the concentration range of 0-10 nM, with a detection limit as low as 24 nM, and exhibited good anti-interference capability and cycling stability. Further spiking-recovery experiments demonstrated excellent detection performance and analytical reliability of the sensor in water and red wine samples.

A novel electrochemical sensing platform was constructed based on a porphyrinic MOF (PCN-224), multi-walled carbon nanotubes (MWCNTs), and gold nanoparticles (AuNPs). The PCN-224/MWCNT composite was first synthesized via a one-pot solvothermal method, followed by the deposition of AuNPs on its surface. The porous structure of PCN-224, the excellent conductivity of MWCNTs, and the catalytic activity of AuNPs collectively enhanced electron transfer efficiency and enabled highly selective recognition of dihydroxybenzenes exemplified by catechol(CC) and hydroquinone (HQ). The resulting PCN-224/MWCNT@AuNPs modified electrode simultaneously quantified HQ and CC across broad linear ranges of 1-1800 mu M (HQ) and 1-1100 mu M (CC), with extremely low limit of detection of 65.6 nM and 85.6 nM, respectively. The electrochemical sensor further exhibited outstanding long-term stability, exceptional repeatability, and robust anti-interference capability. Validated in real environmental samples, its quantification results align closely with those obtained by conventional HPLC, underscoring its high reliability for practical applications. This work provides an effective strategy for applying MOF-based hybrid materials in environmental electrochemical sensing.

A Schiff base fluorescent probe, HTT, based on a sulfonylhydrazone structure was designed and synthesized for the sensitive and selective detection of Cu2+. The probe HTT exhibits good anti-interference performance toward Cu2+ in the presence of a variety of metal ions. After the addition of Cu2+, it can quickly respond within 40 seconds, and the fluorescence detection limit is 1.10 nM. The coordination ratio of probe HTT and Cu2+ is 2 : 1, and the coordination reaction between CN, SO and Cu2+ limits the formation of hydrogen bonds between the hydroxyl group and CN, disrupting the spatial coplanar effect of the probe molecule and thereby inducing fluorescence quenching. The probes can be recovered and reused using EDTA for the detection of Cu2+. The probe was also applied to the successful monitoring of Cu2+ in living cells and real water samples.

Photocatalytic hydrogen peroxide (H2O2) production via the oxygen reduction reaction (ORR) provides a promising and energy-saving alternative to the traditional energy-intensive anthraquinone process. Nevertheless, how to decrease the energy barrier of the two-electron (2e-) ORR process and photosynthesize H2O2 efficiently is still challenging. Herein, three hydroxyl-functionalized donor-acceptor covalent organic frameworks (COFs) are synthesized for photocatalytic H2O2 production under visible-light irradiation (420 <= lambda <= 780 nm). It is observed that the dihydroxyl functionalization (2,5-DhaTph and 2,3-DhaTph) facilitates the transportation of photogenerated carriers between acceptor and donor units and accelerates the kinetics of the rate-limiting step of the ORR when comparing with the monohydroxyl functionalization (2-DhaTph). Further, 2,5-DhaTph with para-position hydroxyl functionalization shows higher H2O2 photosynthesis efficiency than 2,3-DhaTph (ortho-positioned hydroxyl), probably due to the greater exposure of catalytically active sites. This is supported by a better structural symmetry of 2,5-DhaTph, which contributes to higher crystallinity and higher specific surface areas. Electron paramagnetic resonance (EPR) spectra and theoretical calculations show that 2,5-DhaTph produces the *OOH intermediates with a reduced energy barrier, resulting in a high H2O2 production rate of 2103.1 mu mol h-1 g-1. Regulating the amount of hydroxyl substituents and their location on the donor units of COFs is an effective strategy to boost photogenerated carrier transfer and reduce the energy barrier of O2-to-H2O2 conversion.

Tailorable membrane surface architectures are crucial for efficient and precise separation. The nanoemulsion regulation strategy, an emerging technique for constructing nanostructured membranes with tunable architectures, has been scarcely explored for the fabrication of covalent organic framework (COF) membranes. In this work, inspired by the vesicle storage, transport, and release mechanism in human cells and the natural self-assembly of emulsions at interfaces, we proposed a nanoemulsion-directed interfacial polymerization (NDIP) strategy to precisely construct COF membranes with tunable Turing patterns. The introduction of these Turing structures leads to COF membranes with fewer defects and an enlarged surface area, attributable to the nanoemulsion templating effect and the controlled monomer transport mechanism. Short-range van der Waals forces and electrostatic interactions between the nanoemulsions and monomers were elucidated through molecular dynamics simulations and experimental results. Moreover, we systematically explored the effects of variable nanoemulsification space, different internal microenvironments, and emulsifier chain length on membrane separation performance. The designed Turing COF membranes exhibit excellent antibiotic separation ability with a molecular weight cutoff of 289 g/mol and ultrahigh antibiotic/salt selectivity (124.1 for TC/NaCl). This study provides a new design perspective for patterned regulation in COF membranes and highlights the potential of emulsion-guided strategies for advanced molecular separations.

Advanced membrane technology for the separation and purification of active pharmaceutical ingredients (APIs) requires improvement in both membrane materials and manufacturing processes to achieve the high rejection of macromolecular solutes combined with high permeance for organic solvents in pharmaceutical industry. Here, we report a novel approach to preparing aromatic polyamide membranes (PAMs) with tunable microporosity and micropore size via modulator-assisted interfacial polymerization. Enhanced microporosity, increased micropore size, and higher pore interconnectivity of PAMs are achieved by adding ethanol to the aqueous phase to regulate interfacial polymerization, which can be demonstrated through experiments and molecular simulations. The resulting optimal membrane achieves a methanol permeance of 11.9 L m − 2  h −1 bar −1 , representing a impressive 19.8-fold increase compared to commercial benchmark membrane (0.6 L m −2  h −1  bar −1 ) at the same molecular weight cut-off (∼460 g mol −1 ). For practical applications, the optimal membrane demonstrates exceptional capability in the separation of high-value APIs such as dipyridamole, achieving not only accelerated ethanol permeance but also a 6-fold enrichment factor relative to commercial membranes. This work demonstrates the significant potential of phenolphthalein-based microporous polyamide membrane in advancing API separation technologies. It provides valuable insights into the development of next-generation membrane systems tailored for pharmaceutical applications.

Membrane technology has garnered broad concern for its high process efficiency. This study presents an approach to control the microstructure and permselectivity of nanofiltration (NF) membranes by incorporating 18-crown-6 (18C6) or diaza-18-crown-6 (DA18C6). The hydrogen-bonding interactions between crown ethers and piperazine (PIP) decelerate the PIP diffusion during interfacial polymerization, forming thinner polyamide (PA) layers. Furthermore, the constrained PIP diffusion amplifies the differential diffusion kinetics between PIP and trimesoyl chloride, triggering diffusion-driven instability that generates nanoscale striped Turing patterns on the membrane surface. Computational analysis reveals DA18C6's stronger hydrogen-bonding interactions with PIP compared to 18C6, resulting in its superior diffusion inhibition capability. Increasing hydrogen bond density or strength enhances the inhibitory effect of crown ethers on PIP diffusion and facilitates more distinct Turing structures. The crown ether-incorporated PA layers exhibit improved hydrophilicity and microporosity. Benefiting from the optimized physicochemical properties, the modified NF membrane exhibits noticeably enhanced water permeance while sustaining high Na2SO4 rejection. A 115% increase in water permeance is achieved with DA18C6 regulation. Particularly, DA18C6-regulated membranes demonstrate narrowed pore size distribution for precise molecular sieving. This work presents a straightforward strategy utilizing crown ethers for fine-tuning the membrane microstructure and provides fundamental insights into diffusion-mediated membrane fabrication.

Advanced self-standing ionic covalent organic framework membranes (ICOFM) with strong mechanical property and high crystallinity are crucial for expanding the applications of COF membrane, yet it remains a significant challenge. Furthermore, ICOFM, which are often fragile and brittle, typically suffer from trade-off limitation between mechanical strength and high crystallinity, limiting their potential in realms such as separation processes, flexible electronics, and optoelectronics. In this work, a synthetic methodology based on an inorganic ion strategy, a previously underexplored approach, is conceived to prepare hypercrystalline and highly durable ICOFM through electrostatic-assisted interfacial monomers aggregation with enhanced diffusion, reactivity and competitive coordination regulation, fulfilling suitable reaction-diffusion conditions for Turing architecture. The effects of four category inorganic ions, containing (ⅰ) strong acid ions, (ⅱ) weak acid ions, (ⅲ) non-metallic salt ions and (ⅳ) metal cations, on the interfacial polymerization (IP) system are systematically studied through MD simulation, DFT calculation and experimental results. The resulting ICOFM, carrying tunable Turing patterns, demonstrate exceptional mechanical property, asymmetric fluid transport, and molecular sieve capability. These advances will promote future developments in the structural design, efficient synthesis, and high-end applications of COF membrane by reasonably manipulating ion types, offering promising prospects for the advancement of membrane-based technologies.

Polyimide membranes offer the potential of industrial natural gas sweetening to effectively diminish carbon dioxide from raw streams, but it remains a challenge to improve the separation selectivity and further overcome the trade-off limitation through synthesis design. Here, we present an A2+B2+B3 strategy to fabricate a series of polyimides containing hyperbranched network structures by copolymerizing the triamine monomer (TAPA) in conjunction with linear 6FDA-6FAP. The chemical structures and physicochemical properties of polyimides were confirmed by SEM, FTIR, XPS, TGA and XRD. The molar ratio changes of 6FAP/TAPA finely tailored the fractional free volume from 16.9 % to 13.1 % and brought about high packing efficiency, leading to a surge in separation selectivity. The 6FDA-6FAP/TAPA (7:3) membrane exhibited a maximum CO2/CH4 selectivity of 134.5 with a permeability of 26.9 Barrer, improving the CO2/CH4 separation performance of 6FDA-6FAP from far below the 1991 limitation to beyond the 2008 Robeson's upper bound line. Diffusivity and solubility acting as the main factors that govern the gas separation were also carefully investigated. Additionally, 6FDA-6FAP/TAPA (7:3) demonstrated high CO2/CH4 binary gas separation performance, good high-temperature (105 degrees C) reversibility, great plasticization resistance (20 bar) and moderate long-term stability (360 days) under practical working conditions. These results indicate that hyperbranching of polyimide can be successfully controlled to enhance the separation properties, which facilitate the development of high-performance gas separation membranes with topological microstructures.

Nanofiltration and reverse osmosis (RO) are instances of pressure-driven membrane desalination processes (PMDs), which have been extensively employed for seawater desalination due to their great efficiency and environmental friendliness. However, the PMD process is usually limited to thin-film composite polyamide membranes, despite enormous research efforts in recent decades. Here, light-controlled RO COF membranes are developed by using a defect-engineered strategy to chemically rivet spiropyran units into COF channels. The spatial arrangement of spiropyran provides the defect-engineered COF membranes with manageable apertures spanning from 6.9 to 11.1 Å. The COF membrane featuring ordered ultramicropores (6.9 Å, TAPA-TFP-SP-25% COFs) exhibits a preeminent desalinization performance with a NaCl rejection of 91.2%. Furthermore, under light stimulation, the COF channels decorated with spiropyran units are capable of self-regulating the framework structure and hydration conformation by controlling the interconnectivity of confined water clusters, thus achieving hydrated pore size tuning from 11.1 to ∼4.0 Å (from TAPA-TFP-SP-50% to TAPA-TFP-MC-50% COF membrane). Under dark conditions, zwitterionic COF membranes after photoisomerization (TAPA-TFP-MC-50%) exhibit an enhanced KCl rejection (96.2%), representing a 24.1% increase when compared to the COF membrane without interconnected hydrated channels (TAPA-TFP-SP-50%). This membrane channel design concept exploits a viable avenue for developing RO membranes to achieve efficient water purification.

Mixed matrix membranes, with well-designed pore structure inside the polymeric matrix via the incorporation of inorganic components, offer a promising solution for addressing CO 2 emissions. Here, we synthesized a series of novel metal organic cages (MOCs) with aperture pore size precisely positioned between CO 2 and N 2 or CH 4 . These MOCs were uniformly dispersed in the polymers of intrinsic microporosity (PIM-1). Among them, the MOC-Ph cage effectively modulated chain packing and optimized the microporous structure of the membrane. Remarkably, the PIM-Ph-5% membrane shows superior performance, achieving an excellent CO 2 permeability of 8803.4 barrer and CO 2 /N 2 selectivity of 59.9, far exceeding the 2019 upper bound. This approach opens opportunities for improving the porous structure of polymeric membranes for CO 2 capture and other separation applications.

Direct air capture via heterocycles and various flexible MOFs prepared from CO2, heterocycles, and Zn clusters.

A novel hybrid composite integrating conductive poly-3-methoxythiophene and PCN-222(Fe) (porphyrin-metal-organic frameworks) was synthesized using an in situ polymerization strategy. Leveraging the large specific area of MOFs and the low electrical resistance of conductive polymers, the modified electrode proved to be a promising candidate for the electrochemical detection of 4-nitrobenzaldehyde. The electrocatalytic response was measured using differential pulse voltammetry techniques and cyclic voltammetry, where the linear concentration range of analyte detection was estimated to be 0-900 mu M and the detection limit was 0.233 mu M with high selectivity toward the analyte. The sensor demonstrated repeatability and stability, allowing the direct electroanalytical measurement of 4-nitrobenzaldehyde in real samples with reliable recovery. This methodology expands the application of porphyrin MOFs for the electroanalytical sensing of environmental contaminants. Developed a novel hybrid P3MOT@PCN-222(Fe) via in situ polymerization for 4-NBA detection. Showcased broad detection range, high sensitivity, selectivity and stability, laying groundwork for environmental monitoring.

A post-synthetic modification was employed to incorporate lanthanide Eu3+ ions into carbazole-functionalized UiO-67 metal-organic frameworks, successfully fabricating an efficient dual-emission fluorescence probe. The Eu3+-doped composite manifests superior luminescent properties and remarkable fluorescence stability, attributable to the sensitization and reinforcement afforded by the parent framework. Notably, the ligand's capability to capture external light and sensitize Eu3+ emissions led to observing characteristic peaks at 435 nm for the intrinsic ligand and 591, 614, 651, and 701 nm for Eu3+. The introduction of dipicolinic acid (DPA) serves a dual role: it acts as an antenna to absorb photons and replaces the coordinated water molecules of Eu3+, thereby preventing fluorescence quenching by water's O-H vibrations. Additionally, establishing hydrogen bonding between DPA and the carbazole dicarboxylic acid (CDC) initiates an intermolecular charge transfer (ICT) process, enhancing the ligand's fluorescence. Besides, the addition of DPA concurrently enhances the fluorescence emissions of both the ligand and Eu3+, displaying an unusual dual-enhanced "turn-on" fluorescence mode with an impressively low detection limit of 0.538 mu M, accompanied by discernible color changes visible to the naked eye. Utilizing Eu@UiO-67-CDC as a test paper facilitates rapid on-site detection of DPA, eliminating the need for complex instrumentation. Moreover, the Eu@UiO-67-CDC probe can quantify DPA in environmental matrices such as river and lake water, with better recovery rates, indicating its significant potential for practical applications. We have synthesised a lanthanide MOF, Eu@UiO-67-CDC, for the sensitive detection of DPA, offering a practical, instrument-free sensing solution.