Synthesis Of Metal-organic Frameworks Research Articles

Synthesis of UiO-67 Metal-organic Frameworks (MOFs) and their Application as Antibacterial and Anticancer Materials

This study involved the synthesis of the UiO-67 metal-organic framework; UiO-67 is a well-known type of MOF obtained by coordinating the Zr6O4(OH)4 metal unit with the 4,42-biphenyldicarboxylate organic linker, using the hydrothermal technique. The novelty of the current work is to synthesize UiO-67 MOFs, and their application as biological agents for antibacterial and cancer cells. Subsequently, the composite material UiO-67 was subjected to a comprehensive characterization process involving Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), thermal gravimetric analyses (TGA) and surface area analysis, and the results showed the successful synthesis of the UiO-67 MOFs, with a high specific surface area of 1415 m2/g. The­­­ synthesized UiO-67 for its antibacterial properties tested against five pathogenic bacterial strains, which include three gram-positive and methicillin-resistant pairs including MRSA, S. aureus and Enterococcus faecalis, and Two gram-negative bacteria E. colli and S. typhimurium using the agar well diffusion method. These findings have shown enhanced, strong antibacterial activity against all the five used gram-positive and gram-negative bacterial strains. Furthermore, the anticancer efficacy of UiO-67 was evaluated on two distinct types of cancer cells: We are using MCF-7 (human breast cancer cell line) and HepG2 (human liver cancer cells). The experiments prove that UiO-67 has the potential of cytotoxicity against both Glioblastoma and H460 cancer lines with the ability to inhibit apoptosis at the same time.

Cu-based metal-organic framework with dual open metal sites for efficient separation of CO2 from flue gas

Excessive carbon dioxide (CO2) emissions from flue gases intensify the greenhouse effect. Exploring porous adsorbents with high CO2/N2 selectivity is of great significance to reducing the CO2 content in flue gases. Herein, we report a novel PtS-type metal-organic framework (MOFs), termed ZSTU-21, with narrow pore size and excellent CO2/N2 separation performance with dual open copper sites. At 298 K, ZSTU-21 exhibits a CO2 uptake capacity of 62 cm3 g−1 and a high selectivity of 105 for CO2/N2 (CO2/N2 = 15/85, v/v). Multicomponent adsorption breakthrough experiments further verified the superior performance of ZSTU-21 MOF in CO2/N2 separation. Moreover, the synthesis of ZSTU-21 MOF can be carried out under mild experimental conditions at room temperature, making the process simple and cost-effective, thus laying a solid foundation for its widespread application in CO2/N2 separation.

Synthesis of nickel-based metal organic framework using simplified solvothermal method

Synthesis of nickel-based metal organic framework using simplified solvothermal method

Zinc-cluster-based MOF with super selective separation adsorption catalyzes direct chemical conversion of CO2 from quasi-polluted air

The CO2 in the atmosphere has a serious impact on the human living environment. Direct utilization of the discharged CO2 to produce useful chemicals is challenging due to the practical presence of mixed compositions and low concentrations for CO2. Metal-organic frameworks (MOFs) with high internal surface areas, porosity and open metal site potentially possess superior adsorption separation capacity for CO2 gas, and on this basis, it can be used as a catalyst to achieve efficient chemical conversion of CO2. We demonstrate the synthesis and characterization of MOF ([Zn4O(ntba)2]n, MOF 1, H3ntba=4,4',4''-nitrilotribenzoic acid) with excellent selective adsorption properties from quasi- polluted air (O2, N2, CO2, CH4) and as heterogeneous catalysts for direct efficient CO2 chemical conversion. Detailed structural analysis reveals show that zinc ions behave multiple open metal sites and two coordination modes in the polyhedral zinc clusters building unit forming a 3D porous network by polyhedral zinc clusters building unit. Thanks to its structural features, at the 273 K and 100kPa, due to the ideal specific surface area and porosity, MOF 1 have ideal adsorption-separation performance for CO2, its values of adsorption and separation ratio are 75.7 cm3g−1, 373(CO2/N2), 79(CO2/O2), 13(CO2/CH4), respectively. The cycloaddition catalytic reaction investigations show that MOF 1 can be employed as a highly efficient catalyst for converting CO2 with a yield of 78 %. The result of this experiment offers the potential to directly utilize low-concentration and mixed CO2 while avoiding the economic and environmental costs of obtaining purified CO2 feeds tocks.

Probing the Activity and Selectivity of Nickel Carboxylethylphosphonate 2D-MOF for the Electrochemical Conversion of CO2 to Syngas

The increasing concentration of CO2 in the atmosphere is alarming for modern society and the reduction of CO2 into valuable products would be a unique solution.1 Metal–organic frameworks (MOFs), constructed from organic linkers interconnected with metal (oxide) nodes, with high porosity and large surface area, have become an emerging class of electrocatalysts for reduction of CO2.2,3 Herein, we report the synthesis and characterization of a two-dimensional nickel metal-organic framework (2D Ni-MOF) with 3-phosphopropionic acid and 4,4-bypyridine as ligands and Ni2+ as the node (figure 1). The electrocatalytic activity of this material is explored for the electrochemical CO2 reduction reaction (CO2RR). An onset potential for the electrochemical reduction CO2 activity of -0.51 V vs RHE was observed which is 70 mV more positive than the HER in Ar-saturated electrolyte suggesting an efficient CO2 reduction. This catalyst showed a high current density of 33.5 mA cm-2 at 1.01 V vs RHE, exhibiting superior performance to most of the MOFs tested so far for CO2 reduction (figure 2a and b). Long term electrolysis at -0.8 V (vs RHE) yielded a current density of ∼10 mA cm-2 with high selectivity towards the formation of CO and H2 with an average production ratio of 30:70%, respectively (figure 2c and d). This new Ni-MOF catalyst retained its crystallinity and morphology after electrolysis as confirmed by powder XRD, HRTEM, FT-IR and Raman spectroscopy, indicating promising stability of the catalyst.Density functional theory (DFT) was employed to calculate adsorption-free energy of the reaction intermediates to identify the active catalytic sites responsible for CO2 reduction in our 2D Ni-MOF structure. Findings show that the catalyst more readily reduces H* to H2 (with a limiting potential of 0.48 eV) than CO2 to COOH* (limiting potential of 0.78 eV). The reaction mechanism upon which this calculation was based begins with the removal of the H2O molecule bound to the Ni (II) site, followed by CO2 adsorption and the two proton-coupled electron transfer steps yielded COOH* and then CO & H2O. The H2O is more strongly adsorbed to the Ni (II) site than CO which closes the mechanistic cycle. Reference 1. M. J. B. Kabeyi and O. A. Olanrewaju, Frontiers in Energy Research, 2022, 9.2. B.-X. Dong, S.-L. Qian, F.-Y. Bu, Y.-C. Wu, L.-G. Feng, Y.-L. Teng, W.-L. Liu and Z.-W. Li, ACS Applied Energy Materials, 2018, 1, 4662-4669.3. J.-X. Wu, S.-Z. Hou, X.-D. Zhang, M. Xu, H.-F. Yang, P.-S. Cao and Z.-Y. Gu, Chemical Science, 2019, 10, 2199-2205. Figure 1

Recent advances in continuous flow synthesis of metal-organic frameworks and their composites.

Metal-organic frameworks (MOFs) and their composites have garnered significant attention in recent years due to their exceptional properties and diverse applications across various fields. The conventional batch synthesis methods for MOFs and their composites often suffer from challenges such as long reaction times, poor reproducibility, and limited scalability. Continuous flow synthesis has emerged as a promising alternative for overcoming these limitations. In this short review, we discuss the recent advancements, challenges, and future perspectives of continuous flow synthesis in the context of MOFs and their composites. The review delves into a brief overview of the fundamental principles of flow synthesis, highlighting its advantages over batch methods. Key benefits, including precise control over reaction parameters, improved scalability and efficiency, rapid optimization capabilities, enhanced reaction kinetics and mass transfer, and increased safety and environmental sustainability, are addressed. Additionally, the versatility and flexibility of flow synthesis techniques are discussed. The article then explores various flow synthesis methods applicable to MOF and MOF composite production. The techniques covered include continuous flow solvothermal synthesis, mechanochemical synthesis, microwave and ultrasound-assisted flow synthesis, microfluidic droplet synthesis, and aerosol synthesis. Notably, the combination of flow chemistry and aerosol synthesis with real-time characterization is also addressed. Furthermore, the impact of flow synthesis on the properties and performance of MOFs is explored. Finally, the review discusses current challenges and future perspectives in the field of continuous flow MOF synthesis, paving the way for further development and broader application of this promising technique.

Wrinkled metal-organic framework thin films with tunable Turing patterns for pliable integration.

Flexible integration spurs diverse applications in metal-organic frameworks (MOFs). However, current configurations suffer from the trade-off between MOF loadings and mechanical compliance. We report a wrinkled configuration of MOF thin films. We established an interfacial synthesis confined and controlled by a polymer topcoat and achieved multiple Turing motifs in the wrinkled thin films. These films have complete MOF surface coverage and exhibit strain tolerance up to 53.2%. The enhanced mechanical properties allow film transfer onto various substrates. We obtained membranes with large H2/CO2 selectivity (41.2) and high H2 permeance (8.46 × 103 gas permeation units), showcasing negligible defects after transfer. We also achieved soft humidity sensors on delicate electrodes by avoiding exposure to harsh MOF synthesis conditions. These results highlight the potential of wrinkled MOF thin films for plug-and-play integration.

Flexible Metal-Organic Frameworks: From Local Structural Design to Functional Realization.

ConspectusFlexible metal-organic frameworks (MOFs), also known as soft porous crystals, exhibit dynamic behaviors in response to external physical and chemical stimuli such as light, heat, electric or magnetic field, or the presence of particular matters, on the premise of maintaining their crystalline state. The reversible structural transformation of flexible MOFs, a unique characteristic seldomly found in other types of known solid-state materials, affords them distinct properties in the realms of molecule separation, optoelectronic devices, chemical sensing, information storage, biomedicine applications, and so on. The mechanisms underlying their dynamic behaviors can be comprehensively investigated at the molecular level by means of in situ single-crystal or powder X-ray diffraction as well as other in situ spectroscopic techniques due to the high regularity of these crystalline materials during stimuli-responsive phase transitions. Through the introduction of specific stimuli-responsive groups/moieties into the well-defined and ordered molecular arrays, targeted applications can be achieved, and the performance of flexible MOFs can also be further improved via rational structural design.In this Account, we summarize our progress on the design, synthesis, and applications of flexible MOFs over the past few years. First, we highlight the construction principle of flexible MOFs, emphasizing the pivotal role of local structural design. Using an F-modified ligand, a flexible MOF with remarkable structural transformations can be obtained; the regulation of the metal coordination environment and interpenetrating frameworks is also crucial for achieving flexible MOFs. We also propose a strong correlation strategy based on the supramolecular interactions between the guest molecules and the framework, which realizes the temperature-responsive dynamic spatial "open-closed" regulation. Mechanisms of the dynamic behaviors investigated by the in situ techniques were also presented for the obtained materials. Second, some representative specific applications of the newly developed dynamic coordination systems were reviewed. The gas molecule responsive flexible MOFs show efficient short-chain alkane separation properties with discriminatory sorption behavior toward similar gaseous substrates. Smart sensing of temperature, pressure, and volatile organic compounds was achieved by several novel flexible fluorescent MOFs, with optimization potential through state-of-the-art chemical design. Furthermore, multiferroic materials with multiple bistable states and high working temperatures were also obtained based on flexible MOFs.Finally, we provide a discussion of the challenges of flexible MOFs in future research, including precise and efficient synthesis, in-depth structure-property relationship investigation, performance optimization, and industrialization. We hope that this Account will stimulate further research interest in developing next-generation smart materials based on flexible MOFs for applications in challenging chemical separation, extreme environmental sensing, massive information storage, and beyond.

Efficient separation of carbon dioxide and methane in high-pressure and wet gas mixtures using Zr-MOF-808

The capture and separation of carbon dioxide (CO2) has been the focus of a plethora of research in order to mitigate its emissions and contribute to global development. Given that CO2 is commonly found in natural gas streams, there have been efforts to seek more efficient materials to separate gaseous mixtures such as CO2/CH4. However, there are only a few reports regarding adsorption processes within pressurized systems. In the offshore scenario, natural gas streams still exhibit high moisture content, necessitating a greater understanding of processes in moist systems. In this article, a metal-organic framework synthesis based on zirconium (MOF-808) was carried out through a conventional solvothermal method and autoclave for the adsorption of CO2 and CH4 under different temperatures (45–65 °C) and pressures up to 100 bar. Furthermore, the adsorption of humid CO2 was evaluated using thermal analyses. The MOF-808 synthesized in autoclave showed a high surface area (1502 m2/g), a high capacity for CO2 adsorption at 50 bar and 45 °C and had a low selectivity to capture CH4 molecules. It also exhibited a fine stability after five cycles of CO2 adsorption and desorption at 50 bar and 45 °C − as confirmed by structural post-adsorption analyses while maintaining its adsorption capacity and crystallinity. Furthermore, it can be observed that the adsorption capacity increased in a humid environment, and that the adsorbent remained stable after adsorption cycles in the presence of moisture. Finally, it was possible to confirm the occurrence of physisorption processes through nuclear magnetic resonance (NMR) analyses, thus validating the choice of mild temperatures for regeneration and contributing to the reduction of energy consumption in processing plants.

Synergistic effect in ZIF-67/MoS2 entrenched MWCNT photo (electro) catalyst for degradation of tetracycline and alternative to Pt counter electrode in dye-sensitized solar cells

Photocatalytic water purification is an effective environmental protection approach for removing hazardous chemicals in water, besides solar energy conversion is a trustworthy and sustainable choice for the future due to rising energy demands. The present research focus is on synthesis of Metal-Organic Framework (MOF) based composite, Zeolitic Imidazolate Framework-67/Molybdenum Disulfide (ZIF-67/MoS2) entrenched Multi-Walled Carbon Nanotubes (MWCNT) as a catalyst for photodegradation of tetracycline (TC), as well as substitute for Pt counter electrode in Dye-Sensitized Solar Cell (DSSC). The crystalline structure, optical response, shape, porosity, quantum states, and chemical configuration were determined using X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Ultraviolet-Visible Diffuse Reflectance Spectroscopy (UV-DRS), Photoluminescence spectroscopy (PL), Transmission Electron Microscopy (TEM), Brunauer-Emmett-Teller (BET), and X-ray Photoelectron Spectroscopy (XPS), respectively. The degradation efficiency of ZIF-67/MoS2/MWCNT catalyst under effect of operational parameters namely, photocatalyst dosage, solution pH, coexisting ions, TC concentrations and irradiation time were studied consecutively. ZIF-67/MoS2/MWCNT composite achieved 96.1 % degradation efficiency of TC under white light irradiation. Interestingly, when utilized as a counter electrode in DSSCs, this composite-based electrode delivered the highest Power Conversion Efficiency (PCE) of 3.86 % with a short-circuit current density (JSC) of 7.54 mA cm−2 and open-circuit voltage (VOC) of 0.79 V. The observed enhancement is attributed to lesser peak-to-peak separation (EPP), lower electron lifetime, lower charge transfer resistance (RCT) and higher exchange current density (J0). Based on these findings, ZIF-67 inclusion in MoS2/MWCNT composite is not only an effective catalyst for water treatment but also a good catalyst for I3− reduction in DSSCs.

3D Printed Supercapacitors Based on Laser‐derived Hierarchical Nanocomposites of Bimetallic Co/Zn Metal‐Organic Framework and Graphene Oxide

AbstractSupercapacitors (SCs) have the unique ability to rapidly recharge while providing substantial power output. Metal‐organic frameworks (MOFs) are emerging as promising electrode materials for SCs due to their high porosity, ease of synthesis, tunable pore size distribution, and exceptional structural adaptability. This study presents a facile and cost‐effective method, namely, laser ablation synthesis in solution (LASiS), for the synthesis of bimetallic MOFs composited with reduced graphene oxide (rGO), namely, ZnCo bi‐MOF‐rGO hybrid nanocomposite (HNC). Comprehensive analyses demonstrate that ZnCo bi‐MOF‐rGO has a high specific capacitance of 1092 F g−1 at 1.0 A g−1 in a 0.5 M Na3SO4 electrolyte. In addition, these bi‐MOF‐rGO composites have been successfully integrated with appropriate solvents, viscosity modifiers, in‐house synthesized porous carbon (PC), commercially available graphene, and binders into an active layer ink material for the development of high‐performance 3D printed SCs via sequential inkjet printing. To that end, the way has been paved for the incorporation of this class of material into energy storage applications, particularly in the fabrication of high‐performance printed electronics using laser‐induced materials.

High performance oxygen reduction and evolution reactions by graphitization of nickel –cobalt framework system

This study presents the successful synthesis of metal-organic frameworks (MOFs) via a simple one-pot method, followed by pyrolysis at 1000 °C to be used in the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). A study utilizing various techniques, including field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM), and X-ray diffraction (XRD), investigated the properties of NiCo-MOF and its individual components before and after pyrolysis.The pristine MOFs exhibited limited electrochemical stability for both ORR and OER, while the pyrolyzed MOFs demonstrated a significant enhancement and excellent long-term stability in OER and ORR performance in alkaline media. Notably, the OER performance rivaled that of the benchmark IrO2 electrocatalyst, with similar onset potentials (1.48 V for IrO2, 1.52 V, 1.56 V, and 1.59 V for pyrolyzed NiCo-MOF, Co-MOF, and Ni-MOF, respectively). Furthermore, the pyrolyzed MOF catalysts displayed promising ORR activity in a 0.1 M KOH solution under O2 saturation, as evidenced by their onset potentials (around 0.615 V, 0.63 V, and 0.7 V vs. RHE) and favorable Tafel slopes (53, 84, and 154 mV dec⁻1, for graphitizated Ni-MOF, Co-MOF, and NiCo-MOF, respectively). These findings demonstrate the effectiveness of pyrolysis in engineering the MOF crystal structure for enhanced catalytic performance. This paves the way for further exploration of this synthesis method for the design of structurally optimized catalysts and applicable to a broad spectrum of energy technologies.

Optimization of cerium-based metal–organic framework synthesis for maximal sonophotocatalytic tetracycline degradation

Wastewater treatment is inevitably required to alleviate the pollution of water resources by various contaminants such as antibiotics. MOFs are novel materials with photocatalytic activities. In this study, sonophotocatalytic degradation of tetracycline (TC) by the Cerium-based MOF (Ce-MOF) is optimized by modification of its synthesis route. Ce-MOF synthesis by room temperature (RT), hydrothermal (HT), and sonochemical synthesis (SC) are studied. TC degradation experiments revealed the superiority of SC synthesis. The interplay of main synthesis parameters, namely, initial ligand concentration, ultrasound (US) power and time on sonophotocatalytic activity of Ce-MOF, were investigated by response surface methodology model (RSM) utilizing the central composite experimental design (CCD). The optimum SC synthesis conditions are an initial ligand concentration of 8.4 mmol/L, a sonication power of 50 amplitude, and a US time of 60 min. The optimally synthesized Ce-MOF was characterized by infrared spectroscopy, FTIR, XRD, FE-SEM, TEM, zeta potential analysis, diffuse reflectance spectroscopy, particle size analysis, Mott-Schottky analysis, photocurrent analysis, electrochemical impedance spectra, and photoluminescence spectroscopy. The findings indicate that the removal efficiency of TC can reach up to 81.75% within 120 min in an aqueous solution containing an initial TC concentration of 120 ppm and 1 g/L Ce-MOF at pH of 7. Mineralization efficiency of the process is 71% according to COD measurements. The Ce-MOF catalyst retained its chemical stability and remained active upon TC degradation which makes it a promising candidate for wastewater treatment.

Synthesis and Characterization of A Fascinating Coordination Polymer Metal-Organic Framework Featuring Cobalt (II) and 4,4'-Bipyridine

ABSTRACT. This investigation delineates the fabrication, comprehensive characterization, and electrochemical evaluation of a one-dimensional Cobalt-based Metal-Organic Framework (Co-MOFs), constructed from 4,4’-Bipyridine ligands and Cobalt (II) ions. The study aimed to perfect the synthesis protocol, elucidate the structural and compositional attributes of the resultant MOF, and probe its electrochemical performance. Utilizing the reflux method, renowned for its efficacy and eco-compatibility, we synthesized the MOF and affirmed its formation through a suite of analytical techniques, including Infrared (IR) spectroscopy, Ultraviolet-Visible (UV-Vis) spectroscopy, Atomic Absorption Spectroscopy (AAS), and electrical conductivity measurements. The synthesized Co-MOFs, chemically notated as [Co2(4,4'-bpy)2(SO4)(H2O)2]SO4·H2O, manifested as a one-dimensional coordination polymer. X-ray Diffraction (XRD) analysis unveiled its monoclinic crystallinity within the C2 space group. Electrochemical characterization uncovered a reversible redox system, evidenced by a robust peak current ratio (IPa/IPc = 7.5), indicative of efficient electron transfer processes. Furthermore, the Co-MOFs significantly augmented the kinetics of the oxygen evolution reaction (OER) in an alkaline aqueous solution, highlighting its potential as a superior catalyst in energy-related electrochemical applications. This work not only contributes to the field of MOF synthesis but also sets the stage for future explorations into their practical applications in sustainable energy systems. Keywords: Electrochemical properties, metal-organic framework, oxigen evolution reaction catalyst, 4,4’-bipyridine.

Epitaxial Metal-Organic Framework-Mediated Electron Relay for H2 Detection on Demand.

Hydrogen is regarded as one of the most promising clean substitutes for fossil fuels toward a carbon-zero society. However, the safety management of the upcoming hydrogen energy infrastructure has not been fully prepared, in contrast to the well-established natural gas and gasoline systems. On the frontline is the guard post of hydrogen detectors, which need to be deployed on various structural surfaces and environmental conditions. Conventional hydrogen detectors are usually bulky and environmentally sensitive, limiting their flexible and conformal deployment to various locations, such as pipelines and valves. Herein, we demonstrate the successful synthesis of a palladium-modified epitaxial metal-organic framework (MOF) on single-layer graphene to fabricate a heterostructure material (Epi-MOF-Pd). Device based on the heterostructure demonstrates high sensitivity toward low- concentration H2 (155% resistance response to 1% H2 within 12 s, a theoretical detection limit of 3 ppm). The 25 nm epitaxial MOF acquires electrons from the Pd nanoparticles after the trace amount of H2 is chemically adsorbed and further relays the electrons to the highly conductive graphene. The Epi-MOF-Pd is both flexible and enduring, and maintains stable detection over 10 000 bending cycles. Through photolithography, device arrays with a density of 3000 units/cm2 are successfully fabricated. This versatile material provides a prospective avenue for the mass production of high-performance chemical-sensitive electronics, which could significantly improve the hydrogen safety management on demand.

Separable Metal-Organic Framework-Based Materials for the Adsorption of Emerging Contaminants.

Thousands of chemicals have been released into the environment in recent decades. The presence of emerging contaminants (ECs) in water has emerged as a pressing concern. Adsorption is a viable solution for the removal of ECs. Metal-organic frameworks (MOFs) have shown great potential as efficient adsorbents, but their dispersed powder form limits their practical applications. Recently, researchers have developed various separable MOF-based adsorbents to improve their recyclability. The purpose of this review is to summarize the latest developments in the construction of separable MOF-based adsorbents and their applications in adsorbing ECs. The construction strategies for separable MOFs are classified into four categories: magnetic MOFs, MOF-fiber composites, MOF gels, and binder-assisted shaping. Typical emerging contaminants include pesticides, pharmaceuticals and personal care products, and endocrine-disrupting compounds. The adsorption performance of different materials is evaluated based on the results of static and dynamic adsorption experiments. Additionally, the regeneration methods of MOF-based adsorbents are discussed in detail to facilitate effective recycling and reuse. Finally, challenges and potential future research opportunities are proposed, including reducing performance losses during the shaping process, developing assessment systems based on dynamic purification and real polluted water, optimizing regeneration methods, designing multifunctional MOFs, and low-cost, large-scale synthesis of MOFs.

Methane adsorption effect of cyclodextrin-based metal-organic frameworks and ultra-fine water mist composite system in closed container

Natural gas, predominantly composed of methane, is a widely used energy source. Methane is prone to leakage during storage and usage, posing environmental risks. Currently, effective strategies to capture methane leaked in urban environments are lacking. This study investigates the synthesis of a non-toxic Cyclodextrin-based Metal-Organic Framework (CD-MOF) and its adsorption capacity for leaked methane in an ultrafine water mist composite solution system. CD-MOFs, utilizing β-cyclodextrin as the organic ligand and alkali metal potassium as the metal ion, were synthesized via solvothermal and methanol vapor diffusion method. The morphology, functional groups, and thermal properties of CD-MOFs were characterized by multiple techniques. The BET specific surface area, pore structure, and high-pressure methane adsorption capacity of the samples were investigated. Furthermore, CD-MOF, surfactant, and castor oil were combined to create a composite solution absorbent. The methane absorption efficacy of this ultra-fine water mist of absorbent was tested using a closed-container methane spray adsorption apparatus, and the compound solution ratio was optimized. The results indicate that CD-MOFs retain the parent cyclodextrin structure, and the methane adsorption capacity under high-pressure (35 bar) of CD-MOF synthesized by the sodium dodecyl sulfate-assisted solvothermal method reached 216.13 cm3/g. The composite solution with an appropriate proportion of surfactant, castor oil, and CD-MOF reached a methane absorption capacity of 5.7 % vol in enclosed spaces. The successful synthesis of CD-MOFs and the application of composite solutions with ultra-fine water mist offer innovative approaches and theoretical guidance for the emergency absorption and non-toxic disposal of leaked methane.

The Mechanism of Rapid and Green Metal–Organic Framework Synthesis by In Situ Spectroscopy and Diffraction

The Mechanism of Rapid and Green Metal–Organic Framework Synthesis by <i>In Situ</i> Spectroscopy and Diffraction

Synthesis and applications of metal organic frameworks in photodynamic therapy

Metal organic frameworks (MOFs) consist of metal atoms or clusters, coordinated to organic ligands to form macromolecular super structures, with pores large enough to host free drug molecules, including photodynamic therapy (PDT) photosensitizers. This review presents examples of applications in PDT of various types of MOFs. To contextualize the discussions of their PDT applications, general procedures of MOF synthesis are considered. Applications of MOFs in PDT are described using examples of several combination therapy innovations developed for the purpose of solving some of the key challenges in the clinical translation value chain of PDT. The review presents evidence to show that the explosion of research in MOFs is due to their capability for applications as carriers and delivery systems for PDT photosensitizers. It also shows their unique applications as platforms for combination therapies, for stimulus responsive release of photosensitizer and drug molecules, for cancer cell targeting, and for auxiliary enhancement of efficacy. Published literature on MOFs has been on the rise since the eighties. In Scopus, the applications of MOFs in PDT increased from 1 article in 2010, to 169 articles in 2023, whereas published literature on MOFs generally, increased from 878 to 11644 during this period. Research on the applications of MOFs in PDT has therefore increased more than that of MOFs generally. Literature on the applications of MOFs in PDT increased by between 0.7% to 1.45% relative to published literature on MOFs generally. Clearly, MOFs are researched to overcome challenges of and improve PDT efficacy, more than they are generally.

Novel fluorescent sensor with 2,5-furandicarboxylic acid as the ligand for histamine detection

Using effective and sustainable technologies for food quality evaluation has become imperative due to the growing concerns regarding food safety and security. Fluorescent-based sensing is a rapid monitoring technique for food spoilage detection; however, the technique employs fossil-based compounds for sensor development. Here, a fluorescent sensor for histamine (biogenic amine) as an indicator for the detection of spoilage in the fish matrix was fabricated using 2,5-furandicarboxylic acid (FDCA) as the organic ligand. FDCA is a biobased molecule and serves as a replacement for petroleum-derived terephthalic acid, which is widely used in the synthesis of fluorescent metal-organic frameworks (MOF). Herein we report a MOF that was synthesized using two organic ligands: FDCA and adenine with Fe as the metal center, denoted as Fe-AD-FDCA. The fluorescent sensor was created by covalently bonding methyl red (MR) with an NH2-rich Fe-AD-FDCA framework by post-synthetic modification. When exposed to histamine, the sensor showed a fluorescent emissive response that increased MR emission and produced a distinctly visible color shift from dull pink to blue. By spreading and solidifying MR@Fe-AD-FDCA in the water-phase sodium salt of carboxy methyl cellulose (CMC-Na), portable sensory hydrogels were produced. This fluorescence sensor's ability could be utilized for real-time monitoring of the freshness of raw fish samples.