Metal-organic Frameworks Research Articles (Page 1)

Antisense oligonucleotide-loaded nanozyme reverses tumor immune suppression through sonogenetic metabolic therapy.

Bimetallic MOF-hydrogel composites offer a promising strategy for efficient atmospheric water harvesting (AWH) through synergistic moisture sorption and solar-driven water release. Herein, a multifunctional composite (VHN_(CrdAl)M/CaCl2) is developed by integrating a Cr/Al bimetallic metal-organic framework (BMOF) into a thermoresponsive Valine-HEMA-NIPAM (VHN) hydrogel matrix and further loaded with CaCl2. This hybrid material leverages the high surface area and hydrophilicity of the MOF, the porous nature and swelling-deswelling responsiveness of the hydrogel, and the hygroscopic properties of CaCl2. The composite demonstrates superior atmospheric water uptake capability under highly humid conditions (90% RH), reaching up to 4.9 g·g-1. Under 1 kW m-2 solar irradiation, the composite rapidly heats to ∼46 °C within 2 min, enabling efficient water release with a desorption rate of 0.8 g·g-1·h-1. The composite maintains stable performance across multiple sorption-desorption cycles, indicating excellent durability and reusability. Under low-to-moderate humidity conditions, the CaCl2 nanocrystals efficiently incorporated within the porous network demonstrate effective atmospheric water sorption, achieving uptake capacities of 0.85 g·g-1, 1.01 g·g-1, 1.53 g·g-1, and 3.04 g·g-1 at 20%, 40%, 60%, and 80% RH, respectively. These findings establish the developed hybrid as a scalable and energy-efficient material for atmospheric water harvesting in arid environments, offering strong potential for real-world deployment in sustainable water technologies.

Selective in situ growth of metal-organic frameworks (MOFs) within polymeric supports under mild, aqueous conditions remains a synthetic challenge due to interfacial instability, uncontrolled crystallization, and MOF leaching. Here, this study reports a binding-assisted strategy for the selective in-pore growth of MOF-808 within polyacrylonitrile (PAN)/polyvinyl pyrrolidone (PVP) hollow fibers at 30 °C. Alkaline hydrolysis of PAN introduces anchoring sites for zirconium clusters, while ethanol-assisted solvation promotes MOF crystallization under ambient conditions. The spatial distribution and surface charge of hydrolyzed PVP suppress MOF nucleation on the outer surface, enabling uniform in-pore growth with 34 wt.% loading and > 99% retention after ultrasonication. Post-synthetic functionalization with ethylenediaminetetraacetic acid (EDTA) imparts a strong affinity for Pb2+, Ni2+, and Co2+ ions. The EDTA-modified composite exhibits a 2.5-fold increase in Pb2+ adsorption kinetics compared to physically blended counterparts. A modularized 105 cm fiber unit effectively treats 1 L of a mixed-metal solution (10 ppm each), underscoring the scalability and process compatibility of this approach. This work demonstrates a mild, scalable, and leaching-resistant route for fabricating MOF-polymer hybrid sorbents through spatially controlled in-pore crystallization, offering a robust platform for water treatment and metal recovery applications.

The ongoing shift toward energy efficiency and sustainable transportation has intensified the demand for advanced lubrication technologies capable of reducing frictional losses and enhancing mechanical durability. In this context, lubricant additives have emerged as critical components for improving the performance of base oils under extreme operating conditions. Metal-Organic Frameworks (MOFs), with its crystalline porous architecture and tunable physicochemical properties, offer a novel class of additives with significant potential in tribological applications. Their high surface area, structural versatility, and thermal stability enable them to form robust protective films, minimize wear, and provide long-term performance even in demanding environments. MOFs also exhibit low electrical and high thermal conductivity, which makes them especially well-suited for modern lubrication challenges, including those posed by electric vehicle (EV) systems. This review presents an in-depth exploration of MOF-based lubricant additives and their composites, focusing on their tribological behaviors, interaction mechanisms, and potential for achieving superlubricity. It also examines the evolving role of MOFs in addressing lubrication requirements specific to EVs, such as thermal management and material compatibility. By highlighting recent advancements and future prospects, this review underscores the promise of MOF-based materials as next-generation additives for efficient, environmentally friendly lubrication strategies.

Metal-organic frameworks (MOFs) are crystalline materials with exceptionally high surface areas (up to 7000 m2/g), tunable pore structures, and versatile chemical functionalities, making them attractive for diverse environmental and industrial applications. Simultaneously, cold plasma, an ionized, low-temperature gas enriched with reactive species, has gained recognition for its environmentally friendly, rapid, and solvent-free processing capabilities, particularly in material synthesis and surface functionalization. Integrating cold plasma with MOFs presents a synergistic approach that enhances material properties and process efficiency. Recent studies have reported up to a 40%-60% increase in surface reactivity, improved catalyst dispersion by 30%, and reduced particle size to below 100 nm through plasma-assisted synthesis. These hybrid systems have demonstrated enhanced performance in areas such as air and water purification (achieving over 90% pollutant removal), carbon capture (exceeding 4 mmol/g CO2 uptake), energy conversion, and waste-to-resource technologies. Despite their promise, key challenges remain, including scalability, long-term structural integrity, and economic viability. This review also discusses recent advances in MOF design, innovations in plasma engineering, and the potential integration of artificial intelligence to optimize synthesis and functionality. Future perspectives emphasize the importance of green chemistry principles and interdisciplinary collaboration for the development and commercialization of MOF-plasma technologies aimed at sustainable environmental solutions.

The microgeometric structures of Cu play important roles in regulating the catalytic selectivity of CO2 electroreduction. Herein, we fabricated sub-nanometer Cu clusters confined in a metal organic framework (UIO-66-NDC) with certain tetrahedral/octahedral cages for efficient methane (CH4) synthesis. During CO2 electroreduction, Cu clusters confined in UIO-66-NDC exhibited a faradaic efficiency for CH4 as high as 72.0% and a partial current density of -361.0 mA cm-2. Based on in situ characterizations, we revealed that Cu clusters with a coordination number of around 7 were in situ generated in the octahedral cages of UIO-66-NDC during electrolysis. In situ spectroscopy measurements unraveled that *CO with bridge adsorption (*CObridge) was favorable to be adsorbed on the surface of Cu clusters. Theoretical calculations suggested that *CObridge was more inclined to be protonated into *CHO and then into *CH2O rather than going through the C-C coupling path on Cu clusters, thus boosting CH4 selectivity.

The development of systems that can efficiently store and manage thermal energy - i.e., heat - would improve the efficiencies of numerous processes throughout multiple sectors of the global economy. Nevertheless, the development of these thermal storage devices remains at a relatively early stage. To engage more researchers in the development of these devices and to accelerate their commercialization, this review presents an introduction to the properties of thermal storage materials that absorb and release heat through thermochemical reactions. Thermochemical materials typically exhibit the largest energy densities among all approaches to material-based heat storage. Nevertheless, they suffer from limited reaction rates and poor cycle life. An additional challenge is the multiscale nature of the energy storage process, which ranges from atomistic interactions that govern the storage of heat through alteration of chemical bonds, to mesoscale processes that control the transport of mass and heat. Following an overview of general concepts related to thermal energy storage, emphasis is placed on describing properties relevant for low-temperature applications. These applications include domestic heat storage/amplification (hot water heating), adsorptive cooling (air conditioning), and heat-moisture recuperation. Subsequently, detailed introductions are provided to the mechanisms and materials relevant for the three primary approaches to low-temperature thermochemical storage, including: (i) absorption in solids (hydrates, ammoniates, and methanolates); (ii) adsorption in porous hosts (zeolites, metal-organic frameworks); and (iii) dilution in liquids. For each category, advantages and shortcomings of benchmark and emerging materials are discussed. Finally, challenges and opportunities are highlighted for research aimed at developing optimal materials for thermochemical energy storage.

Metal-organic frameworks (MOFs) are an emerging class of porous materials with remarkable surface area, tunable pore structures, and diverse chemical functionalities. In this study, we reported the green synthesis and comprehensive characterization of a novel modified NH2-MIL-101 (Cu) derived from 2-aminoterephthalic acid, followed by post-synthetic modification with terephthalaldehyde to improve its adsorption capabilities. The synthesized Cu-MOF exhibited a very high specific surface area (2037.65m2·g-1, BET), a total pore volume of 0.7465cm2·g-1 and mesoporosity with an average pore diameter of 29.06nm. SEM and TEM images showed uniform polyhedral particles with an average particle size of ≈ 85 ± 10nm, while XRD patterns displayed well-defined diffraction peaks with the most intense reflection at ~ 2θ = 28-29°, confirming high crystallinity and preservation of the MIL-101 topology after modification. Under optimized conditions (10mg adsorbent, 10 mL solution, room temperature and appropriate pH), the material exhibited high adsorption capacities of 230.1, 165.2, and 187.4mg·g-1 for crystal violet, methyl orange, and rhodamine B, respectively, attributable to its large porosity and functional surface groups. A plausible mechanism involving electrostatic interaction, π-π stacking, and coordination bonding is proposed for adsorption of dyes onto the modified MOF. The Cu-MOF maintained excellent structural stability and reusability, retaining over 92% of its initial adsorption capacity after five consecutive adsorption-desorption cycles, as confirmed by XRD patterns showing no noticeable framework collapse. This highlights its robustness and potential for sustainable wastewater remediation. In addition to dye removal, the material demonstrated antimicrobial activity, with MIC values of 4, 8, 32 and 128µg/mL for P. aeruginosa, C. albicans, E. coli, and A. fumigatus, respectively, while no inhibition was observed against Gram-positive strains at concentrations up to 4096µg/mL. The antimicrobial effect is likely attributed to Cu2+ ion release and electrostatic interactions leading to membrane disruption and ROS generation. These results highlight the potential of the synthesized Cu-MOF as a multifunctional and eco-friendly candidate for both wastewater treatment and biomedical applications.

Nanomaterials offer enhanced stability and functionality for photothermal agents; however, their efficacy is often limited by suboptimal cellular internalization and photothermal conversion efficiency. To address these challenges, we designed a multicomponent inorganic-organic hybrid photothermal agent that integrates a virus-mimicking morphology and stimuli-responsive components. Gold nanostars (GNS) were functionalized with a pH-responsive epigallocatechin gallate (EGCG) polyphenol network, followed by in situ growth of CuS, yielding star-shaped GEC nanoassemblies with a rough surface. This biomimetic design leverages (i) the plasmonic photothermal properties of the GNS core, (ii) the acid-triggered disassembly of the EGCG network (mimicking viral protein shells), and (iii) the in situ synthesized CuS layer exhibiting a virus-mimetic rough surface and targeting capability, which enhances near-infrared light absorption and promotes endocytosis by the target cells. The synergistic integration of GNS and CuS significantly enhanced the photothermal conversion efficiency. Under tumor acidic conditions, the EGCG network disintegrated, leading to the shedding of the CuS shell and a reduction in overall size, which facilitated deep tissue penetration. Structural characterization confirmed the hierarchical architecture and pH-responsive size transition. Compared to unmodified GNS, the cellular uptake of GEC by 4T1 cells was approximately 4.5-fold higher, attributable to its virus-like rough surface, acid-responsive disintegration, and targeting ability. This work demonstrates a rational biomimetic strategy for engineering stimuli-responsive inorganic-organic hybrids with optimized photothermal performance through biomimetic component engineering.

M2-type tumor-associated macrophage (TAM)-dominated immunosuppressive tumor microenvironment (TME) often contributes to chemoresistance. For the first time, a glutathione (GSH)-responsive metal-organic framework (MOF) nanoinducer is engineered for co-delivering doxorubicin (DOX) and HIF-1α antisense oligonucleotide labeled with Ce6 photosensitizer. This new crystal structure exhibited robust stability in simulated physiological environments. Furthermore, multimodal synergistic effects are exhibited upon tumor cell internalization with the nanoinducer. GSH depletion synergizes with photodynamic therapy (PDT) generated reactive oxygen species (ROS) to induce ferroptosis, which effectively drives phenotypic reprogramming of M2-TAMs toward M1 macrophages. HIF-1α antisense oligonucleotides downregulate HIF-1α expression as well as downstream P-glycoprotein (P-gp) mediated drug efflux, thereby significantly enhancing DOX accumulation in chemoresistant breast cancer cells. Consequently, the combination of DOX with ferroptosis-induced immunogenic cell death (ICD) initiates antitumor immunity and activates cytotoxic T lymphocytes. This smart biomimetic nanoinducer demonstrates robust antitumor performance in both in vitro and in vivo models, effectively activating tumor-specific immune responses. A promising candidate nanodrug with a new crystal structure is presented for chemotherapy-immunotherapy combination therapy.

In this study, we construct a glutathione (GSH)-activated DNA nanodevice conjugated to a porphyrin-based metal-organic framework (PCN-224), creating an integrated theranostic platform for modulating hypoxia, enabling miRNA-210-specific imaging and enhancing photodynamic therapy (PDT).

Nowadays, new electrode materials for energy storage devices like mixed ligands and bi-metal MOFs have attracted a lot of attention owing to their high porosity and high capacity for charge storage. In this study, a Co-based metal-organic framework (4,4'-bpy = 4,4'-Bipyridine and H3BTC = 1,3,5-Benzenetricarboxylic acid) was successfully fabricated by a hydrothermal method. To obtain good electrochemical behavior, Co-MOFs were modified using a porous spherical scaffold of NiS/Ni3S4 nanoparticles. The electrochemical efficiency was analyzed by electrochemical impedance spectroscopy, cyclic voltammetry, and galvanostatic charge-discharge methods. Detailed electrochemical scrutiny performed by Co-MOF/NiS-Ni3S4 in a 6M KOH electrolyte reveals a high specific capacity of 136.67 mAh/g at 1A/g, with a superb cycle life of 91%. Co-MOF/NiS-Ni3S4//AC asymmetric supercapacitor produces a large amount of energy density (33.32 Wh/kg) and power density (600W/kg). The produced composite is an appropriate candidate for electrodes in both batteries and hybrid supercapacitors, owing to its favorable electrochemical characteristics.

This study introduces a novel and environmentally relevant sample preparation strategy for the trace-level determination of hazardous phenolic pollutants in complex wastewater matrices. Unlike conventional extraction methods that merely tolerate matrix interferences, this approach eliminates them before analyte extraction, improving selectivity and reliability. A magnetic core-shell metal-organic framework was employed to selectively adsorb interfering substances from real wastewater samples collected from pharmaceutical, municipal, and petrochemical sources. This material was characterized using scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy, vibrating sample magnetometry, and Brunauer-Emmett-Teller surface analysis. Its magnetic responsiveness allowed for simple and rapid phase separation without the need for centrifugation. Following matrix cleanup, phenolic compounds were derivatized using acetic anhydride in the presence of sodium carbonate and extracted using a vortex-assisted liquid-liquid microextraction technique. The optimized method required minimal amounts of sorbent and organic solvents, improving its environmental sustainability and reducing laboratory waste. Coupled with gas chromatography and flame ionization detection, the method demonstrated excellent analytical performance, with relative standard deviations between 1.0 and 8.3% (for 10 µg L⁻1), recoveries ranging from 62 to 83%, correlation coefficients above 0.9962, and low limits of detection and quantification. Application to real wastewater samples showed recoveries between 81 and 118%, confirming the method's effectiveness in eliminating matrix interferences and accurately determining phenolic pollutants.

The rational design of adsorbents with optimal structural features for C2H2/CO2 separation remains challenging because of their similar molecular features. Herein, we synthesized a series of isostructural flexible MOFs (M-bz, M = Co, Ni, and Zn, bz = 5-(3,5-dimethyl-1H-pyrazol-4-yl) isophthalic acid), where the structural flexibility and pore architectures are regulated by the metal nodes. They display selective adsorption of C2H2 over CO2, with Co-bz demonstrating the highest C2H2/CO2 selectivity and uptake ratio of 5.36 and 2.71, respectively. The separation capability was validated by multicomponent breakthrough measurements. This has been attributed to its optimal flexibility and pore surface chemistry, providing multiple hydro-gen bonds (C-H···N and C-H···O) and C-H···π interactions for enhanced C2H2 adsorption affinity.

Chiral discrimination by a simple and efficient sensing means is highly desirable but a challenge for the study of chiral compounds. In this work, a chiral metal-organic framework (CMOF) with a tailored channel size is combined for the first time with electrochemiluminescence (ECL) in a synergistic approach to construct a chiral recognition ECL (CR-ECL) system for efficient discrimination of tryptophan (Trp) enantiomers. Notably, Trp functions dually as both the analyte and the co-reactant, generating distinct ECL signals in the presence of the luminophore (sodium tetraphenylborate, TPB). The chiral-functionalized MOF808-His, with its precisely designed channels and pores, preferentially permits the transport and oxidation of L-Trp, leading to a significantly stronger luminescence signal compared to D-Trp. Owing to the enantioselective recognition enabled by the unique chiral channels, a high recognition efficiency is achieved with an ECL intensity ratio (ECLL/ECLD) of 13.4, demonstrating excellent ECL enantioselectivity. This study pioneers a novel strategy for developing CR-ECL systems based on the channel-engineered CMOF. It not only offers a simple, rapid, and cost-effective approach for enantioselective recognition but also innovatively advances the application of channel-engineered CMOF in chiral discrimination and ECL-based bioassays.

The rapid identification of arsenic speciation is critical for assessing its toxicity and guiding emergency response during water contamination events, yet it remains a significant challenge for current analytical methods. Herein, a novel machine learning-driven fluorescent sensor array was designed for the differentiation of four arsenic species, including arsenite (AsIII), arsenate (AsV), monomethylarsonic acid (MMAV), and dimethylarsinic acid (DMAV). Two Fe-based luminescent metal-organic frameworks (NH2-MIL-88(Fe) and OH-MIL-88(Fe)) were synthesized by functionalizing MIL-88 (Fe) with 2-amino-terephthalic acid and 2-hydroxy-terephthalic acid, respectively, both of which presented promising fluorescence behavior. Remarkably, varying arsenic species differentially regulated the fluorescence intensity of NH2-MIL-88(Fe) and OH-MIL-88(Fe), which was further analyzed by pattern recognition methods to develop a fluorescence sensor array for the rapid, simultaneous identification of four arsenic species and their mixtures. Furthermore, a machine learning algorithm was employed to integrate with the fluorescent sensor array to establish a stepwise prediction model to precisely identify and predict four arsenic species, which was successfully applied to actual water samples. Thus, our findings presented a robust, rapid, and intelligent platform for arsenic speciation, offering a powerful tool for water quality assessment and emergency response.

Per- and polyfluoroalkyl substances (PFAS), known as "forever chemicals," present major environmental and health risks due to their extreme stability and dual hydrophobic-hydrophilic character, which complicates remediation. Conventional adsorbents such as activated carbon and ion-exchange resins show limited performance, particularly for short-chain PFAS. Metal-organic frameworks (MOFs) have emerged as promising alternatives owing to their tunable porosity, large surface area, and adjustable functionality. Here, we assess the PFAS removal potential of a robust, water-stable, biologically derived MOF, CuII 2(S,S)-hismox·5H2O (denoted 1), synthesized from L-histidine. MOF 1 features medium-sized trapezoidal nanoscale channels exhibiting both hydrophobic and hydrophilic character. It achieved high capture efficiencies (80-100%) for long-chain PFAS (C₇-C₁2), including PFDA, PFUnDA, PFDoDA, PFOS, and 8:2 FTSA, and remarkable removal rates of 70% (PFBA) and 86% (PFBS) for short-chain analogues -surpassing conventional adsorbents and other reported MOFs. Excellent reusability and rapid adsorption kinetics were observed under continuous-flow solid-phase extraction with contact times under 30 seconds. The high crystallinity of MOF 1 also enabled single-crystal X-ray diffraction studies of encapsulated PFBA and PFOS (PFBA@1 and PFOS@1). These findings highlight MOF 1 as a high-performance, bio-derived platform for efficient PFAS remediation and advance the development of MOF-based water treatment technologies.

Per- and polyfluoroalkyl substances (PFASs) are a category of extremely persistent environmental pollutants. Metal-organic frameworks (MOFs) have appeared as promising adsorbents for PFAS removal due to their large surface area, tunable porosity, and versatile surface chemistry, which are among the numerous treatment technologies available. This review critically evaluates current developments in the design, fabrication, and application of MOF-based (nano)materials for the adsorption of PFAS in aqueous environments. The adsorption efficacies of MOFs (e.g., pore size, surface charge, and functional groups) and PFASs (e.g., chain length, head group functionality, and polarity) are significantly influenced by their physicochemical properties. The selective and efficient removal of PFASs is governed by the interaction mechanisms such as electrostatic attraction, hydrophobic interactions, H-bonding, and Lewis acid-base coordination. In addition, the adsorption efficacy is significantly influenced by water quality conditions, including pH, ionic strength, background ions, and natural organic matter. Functionalized MOFs (e.g., those with amine, fluorinated, or hydrophobic groups) exhibit resilience to interference, although these factors can sometimes hinder their removal. Both experimental and computational studies have provided valuable mechanistic insights into the rational design of MOFs with improved selectivity and capacity. In addition, this review identifies critical challenges and future perspectives, such as the necessity of standard performance testing under realistic water matrices; the development of scalable, stable, and regenerable MOFs; and their integration into life-cycle assessment and toxicity evaluation.

The conversion of CO2 into quinazoline-2,4(1H,3H)-diones is a vital process in the pharmaceutical industry; however, developing efficient catalysts to realize ultrafast reaction rates remains challenging due to the complex reaction steps. Herein, the novel metal-organic framework {[(CH3)2NH2][Co3(μ3-OH)(BTB)2(BPT)]·4DMF·2H2O}n (Z-1) was synthesized, exhibiting high solvent and thermal stability, and featuring asymmetric [Co3]-clusters, abundant open metal sites, and nanocages. Remarkably, Z-1 catalyzed the reaction between CO2 and 2-amino-N-methylbenzamide at an ultrafast rate, achieving a 92% yield of 3-methylquinazoline-2,4(1H,3H)-diones within 2 min at room temperature. Its turnover frequency (613 h-1) is the highest value recorded in all catalytic systems for synthesizing quinazoline-2,4(1H,3H)-diones. Additionally, Z-1 accommodated 16 diverse substrates and maintained a high yield over ten catalytic cycles. Mechanistic studies revealed that the [Co3]-clusters effectively activated the amino group of substrates (the rate-determining step), while the thiadiazole moieties created alkaline microenvironments that enriched and activated CO2. Density functional theory calculations further confirmed that Z-1 effectively reduced the activation energy barrier of the rate-determining step, thereby accelerating the generation of the carbamate intermediate from CO2 and 2-aminobenzamide. This work presents the first heterogeneous catalyst capable of efficiently catalyzing the reaction between 2-aminobenzamide and CO2, providing new insights into the design of catalysts for the chemical fixation of CO2.

Zirconium-based metal-organic frameworks (MOFs) for advanced nanofiltration applications: a minireview