Zeolitic Imidazolate Framework Research Articles

Cytotoxic effects of bee venom-loaded ZIF-8 nanoparticles on thyroid cancer cells: a promising strategy for targeted therapy.

Thyroid cancer continues to be a notable health issue, requiring the creation of novel treatment methods to enhance patient results. The objective of this study is to investigate the potential of utilizing bee venom (BV)-loaded zeolitic imidazolate framework-8 (ZIF-8) nanoparticles as a novel strategy for specifically targeting and treating medullary thyroid cancer cells. Due to their wide surface area and configurable pore size, ZIF-8 nanoparticles are ideal for drug delivery. Bee venom's cytotoxic capabilities are used in ZIF-8 nanoparticles to target thyroid cancer cells more effectively. ZIF-8 nanoparticles containing bee venom were tested on TT medullary thyroid cancer cell lines. The effects of these nanoparticles on cell viability, proliferation, and apoptosis were investigated. IC50 value at 24h for BV-ZIF-8 nanoparticles in TT medullary thyroid carcinoma cells was determined to be 17.19µg/mL, while the IC50 value at 48h was determined to be 16.39µg/mL. It has been demonstrated that nanoparticle treatment upregulates the Bax and caspase-3 genes while downregulating the Bcl-2, CCND1, and CDK4 genes. Additionally, it was observed that oxidative stress was triggered in the nanoparticle-treated group. Furthermore, an examination of its mechanisms was conducted, with a specific emphasis on the modulation of critical signaling pathways that are implicated in the progression of cancer. In thyroid cancer cells, ZIF-8 nanoparticles infused with bee venom promote programmed cell death and impair key biological processes.

Recent Advances in Single‐Atom Catalyst for Solar Energy Conversion: A Comprehensive Review and Future Outlook

AbstractSingle‐atom catalysts (SACs) are becoming increasingly recognized as highly promising catalytic materials, distinguished by their exceptional atomic efficiency, superior selectivity, and elevated activity levels. This review offers a detailed and comprehensive overview of the recent advancements in SACs, focusing on synthesis strategies, photocatalytic energy conversion applications, and advanced characterization techniques. Various synthetic approaches for fabricating atomically dispersed catalysts are elaborated concisely, emphasizing the importance of achieving precise atomic regulation on compatible supports to ensure strong metal–support interactions. Furthermore, the advanced characterization techniques by analytical tools are illustrated for a deep exploration of catalytic activity and mechanistic insights into uniformly dispersed SACs. Specifically, different kinds of support materials such as metal–organic frameworks (MOFs), their subset zeolitic imidazolate frameworks, and graphitic carbon nitride (g‐C3N4) with diverse coordination and electronic environments are examined. Further, advances in computational techniques and machine learning are transforming SACs development by improving predictive accuracy and reducing trial‐and‐error methods, thereby accelerating the discovery of stable and active catalysts. Finally, current challenges and prospects of SACs based on MOFs, and g‐C3N4 are addressed, providing valuable insights for the continued development and application of these catalysts in various industrial processes and environmental remediation efforts.

Engineering of HO–Zn–N2 Active Sites in Zeolitic Imidazolate Frameworks for Enhanced (Photo)Electrocatalytic Hydrogen Evolution

Currently, lack of ways to engineer specific and well‐defined active sites in zeolitic imidazolate frameworks (ZIFs) limits our fundamental knowledge with respect to the mechanistic details for (photo)electrocatalytic hydrogen evolution reaction (HER). Here, we introduce the open metal sites into ZIFs through the selective ligand removal (SeLiRe) strategy, comprehensively characterize the altered structural and electronic features, and evaluate their role in HER. In‐situ electrochemical analysis and X‐ray absorption spectroscopy reveal the formation of high‐valence HO−Zn−N2 sites through the binding of Zn−N2 with electrolyte hydroxide. The optimal OMS‐ZIF exhibits a low overpotential of 0.41 V to achieve an ampere‐level 1.0 A cm−2 with 120‐hour stability. Theoretical simulations indicate that these active sites accelerate the water molecules activation kinetics, consequently enhancing the efficiency of the Volmer step. This work demonstrates a versatile strategy to introduce highly active catalytic sites in ZIFs, providing new insights into the electrocatalytic mechanism in alkaline media.

Construction of silver-doped graphitic carbon nitride integrated zeolitic imidazolate framework as an ultra-sensitive probe for colorimetric detection application

Abstract Malachite green, and phloxine B are highly effective antifungal, and antibacterial agents utilized primarily in aquaculture. It is classified within the Triarylmethane dye. Numerous studies have indicated that malachite green, and phloxine B are significantly toxic to both terrestrial and aquatic organisms. More critically, it poses substantial risks to human health and safety. As a result, several governments have prohibited its application in aquaculture and food production. There is a pressing need to develop a novel colorimetric probe for the detection of malachite green, and phloxine B. In response, a composite material was synthesized, combining Zeolitic Imidazolate Framework (ZIF-8) with silver-doped graphitic carbon nitride (Ag-g-C3N4), to serve as a colorimetric probe for the sensitive and selective identification of malachite green, and phloxine B. The Ag-g-C3N4/ZIF-8 composite demonstrated exceptional colorimetric sensing capabilities, attributed to the synergistic interactions between ZIF-8 and Ag-g-C3N4, achieving a detection limit as low as 1.073 nM, and 1.214 nM, for malachite green, and phloxine B, respectively. This composite represents a significant advancement in environmental sensing technology, providing a versatile and effective approach for detecting and addressing contamination in water resources.

Increasing the dual-enzyme cascade biocatalysis efficiency and stability of metal-organic frameworks via one-step coimmobilization for visual detection of glucose.

In biosensing analysis, the activity of enzyme systems is limited by their fragility, and substrates catalyzed by monoenzymes tend to undergo spontaneous decomposition during ineffective mass transfer processes. In this study, we propose a novel strategy to encapsulate the glucose oxidase and horseradish peroxidase (GOx&HRP) cascade catalytic system within the hydrophilic zeolite imidazole framework ZIF-90. By leveraging the specific pore structure of ZIF-90, we effectively immobilized GOx and HRP molecules in their three-dimensional conformations, which improved the catalytic activity of the encapsulated enzymes compared with that of free GOx and HRP in various harsh environments. Additionally, our strategy reduced the occurrence of ineffective mass transfer and enhanced the sensitivity of the biosensor through an enzyme cascade system. When this biosensor was applied to serum samples containing complex biological matrices, the degradation of GOx&HRP by various proteases and the surface adsorption of diverse biomolecules were effectively prevented, thereby generating stable and reliable signals of glucose levels. The sensor shows remarkable sensitivity and selectivity for determining glucose concentrations ranging from 0 to 2.5 μg ml-1, with a detection limit as low as 0.034 μg ml-1. Furthermore, we developed a paper-based colorimetric sensor utilizing GOx&HRP@ZIF-90 integrated with a smartphone platform for the visual detection of blood glucose.

Direct In Situ Fabrication of Strong Bonding ZIF-8 Film on Zinc Substrate and Its Formation Mechanism

There is much promise for creating metal organic framework (MOF) films on metal substrates in fields including sensing and electrical conduction. For these applications, direct production of MOF films with strong bonding on metal substrates is extremely desirable. In this study, a simple one-step method without the need for additives or pre-modification is used to directly create zeolitic imidazolate framework-8 (ZIF-8) films with strong bonding on zinc substrate. The formation mechanisms of ZIF-8 film are analyzed. The strong bonding ZIF-8 film can be attributed to an in-situ grown ZnO interlayer between the ZIF-8 and substrate. The growth process shows the formation time of zinc oxide on the substrate, which is subsequently covered by ZIF-8 crystals. The ZnO interlayer results from a combination of decomposition products of the solvent and the zinc ions. Furthermore, the ZnO interlayer serves as a sacrificial precursor for the in-situ nucleation and continuous growth of ZIF-8 film. It serves as an anchoring site between ZIF-8 film and substrate, resulting in strong adhesion. This paper describes a simple and straightforward production process that is expected to provide a theoretical basis for the laboratory preparation of ZIF films.

Polystyrene-MOF-Derived 3D Hierarchical Porous Carbon for High-Performance Supercapacitors.

The ability to tailor surface area, porosity, and morphologies has driven extensive research into the synthesis of metal-organic frameworks derived carbons and their applications in energy storage. This study presents the development of three-dimensional hierarchically porous carbon derived from polystyrene and small-sized zeolitic imidazolate framework-8 (ZIF-8) particles. Incorporating nanometer-sized ZIF-8 particles forms a core-shell structure in the pre-carbonization stage, transforming into a porous carbon material with a range of pores from micro to macropores after carbonization. The carbonized material's electrode demonstrates a high capacitance of 428.8 F g-1 at 1 mV s-1 in the three-electrode setup and a very high specific energy of 48.75 Wh kg-1 at 50 mA g-1 in the packed flat cell configuration. This exceptional electrochemical performance is attributed to the composite carbon material's high surface area, well-developed pore structure, and self-doped nitrogen content.

2D MOF Structure Tuning Atomic Ru Sites for Efficient and Robust Proton Exchange Membrane Water Electrolysis.

Developing cost-effective ruthenium (Ru)-based HER electrocatalysts as alternatives to commercial Pt/C is crucial for the advancement of proton exchange membrane water electrolysis (PEMWE). However, the strong hydrogen adsorption of Ru-based catalysts restricts its activity. Herein, a strategy is reported to tune the electronic structure and improve mass transfer by implanting Ru atoms onto the (002) facet of two-dimensional zeolitic imidazolate framework-67(Ru@LZIF(002)) to optimize the d-band center (εd) of Ru and the hydrogen spillover behavior. Benefiting from the ultrathin nanosheet structure and optimized εd of Ru, the over-strong H adsorption energy is weakened and the electron/mass transfer is facilitated. Ru@LZIF(002) exhibits an overpotential of 9.2mV at 10mA cm-2 and a long-lasting stability of 35 days at 100mA cm-2. The mass activity and price activity of Ru@LZIF(002) is 2.9 and 14.7 times higher than Pt/C, respectively. More impressively, Ru@LZIF(002) delivers a cell voltage of 2.01V at a high current density of 4 A cm-2 in PEMWE. The excellent long-term durability of 1200 hours operating at 4 A cm-2 with an ultralow decay rate of 7.5 × 10-3mV h-1 has been achieved, making it promising as a cost-effective alternative to Pt/C catalyst for PEMWE applications.

Mn and Zn-Doped Multivariate Metal-Organic Framework as a Metalloimmunological Adjuvant to Promote Protection Against Tuberculosis Infection.

A first-in-class vaccine adjuvant delivery system, Mn-ZIF, is developed by incorporating manganese (Mn) into the zinc-containing zeolitic-imidazolate framework-8 (ZIF-8). The mixed metal approach, which allowed for tunable Mn doping, is made possible by including a mild reducing agent in the reaction mixture. This approach allows up to 50% Mn, with the remaining 50% Zn within the ZIF. This multivariate approach exhibits significantly decreased cytotoxicity compared to ZIF-8. The porous structure of Mn-ZIF enables the co-delivery of the STING agonist cyclic di-adenosine monophosphate (CDA) through post-synthetic loading, forming CDA@Mn-ZIF. The composite demonstrated enhanced cellular uptake and synergistic activation of the cGAS-STING pathway, producing proinflammatory cytokines and activating antigen-presenting cells (APCs). In a preclinical Mycobacterium tuberculosis (Mtb) model, CDA@Mn-ZIF formulates with the CysVac2 fusion protein elicited a potent antigen-specific T-cell response and significantly reduced the mycobacterial burden in the lungs of infected mice. These findings highlight the potential of CDA@Mn-ZIF as a promising adjuvant for subunit vaccines, offering a novel approach to enhancing vaccine efficacy and protection against infectious diseases such as tuberculosis.

Lab-on-Fiber Operando Deciphering of a MOF Electrocatalyst.

Despite the great success in deploying metal-organic frameworks (MOFs) as efficient electrocatalysts, the low adoption of operando methods hinders the understanding of underlying mechanism. By leveraging the subtle refractive index evolution, including both the real and the imaginary parts, an entirely new concept of a lab-on-fiber operando method and its feasibility for "pristine-immersion-operando-post analysis" of electrocatalyts are demonstrated. Concurrent collection of absorption spectra and surface plasmon resonance is achieved by engineering fiber-optic waveguidesto simultaneously induce guided light attenuation and plasmonic coupling. In situ-formed Co hydroxide and oxide reactive intermediates in zeolitic imidazolate framework-67 (ZIF-67) electrocatalyst are optically identified, whichshows its underlying self-reconstruction conversions at different stages during electrocatalytic oxygen evolution reactions, and address the gap in knowledge concerning whether ZIF-67 is a precatalyst for real catalyst production. This illuminating operando method offers intriguing opportunities to collect all the observables in a single fiber, provides an exciting potential of a new class of device with long-sought integration and miniaturization capability, and is expected to enable the electrocatalysis community to conquer challenges with conducting multimodal operando experiments outside the laboratory.

Optimization of hydrogen storage at ambient temperature via central composite design using hybrid nanocomposites of zeolitic imidazolate frameworks-8 incorporated rice husk graphene-like as adsorbent

Optimization of hydrogen storage at ambient temperature via central composite design using hybrid nanocomposites of zeolitic imidazolate frameworks-8 incorporated rice husk graphene-like as adsorbent

Electrodeposition of Ruthenium onto Cobalt − Nitrogen-Doped Carbon Derived from a Zeolitic Imidazolate Framework for Enhanced Hydrogen Evolution Reaction

Electrodeposition of Ruthenium onto Cobalt − Nitrogen-Doped Carbon Derived from a Zeolitic Imidazolate Framework for Enhanced Hydrogen Evolution Reaction

Mesoporous silica-modified metal organic frameworks derived bimetallic electrocatalysts for oxygen reduction reaction in microbial fuel cells

The design of cost-effective oxygen reduction reaction (ORR) catalysts in microbial fuel cells (MFCs) remains a challenge. Herein, a mesoporous silica (mSiO2) assisted protection strategy is developed to synthesize highly dispersed CuCo nanoalloys embedded in nitrogen doped carbon Cu/Co-NC@mS catalyst using zeolitic imidazolate framework (ZIF) as carbon and nitrogen sources. The results revealed that the mSiO2 protection holds the potential to inhabit CuCo nanoalloys from aggregation and thus promotes the formation of highly dispersed small CuCo nanoparticles. The obtained catalyst with pyrolysis temperature (T) of 800 °C (Cu/Co-NC@mS-800) achieves the best ORR performance among Cu/Co-NC@mS-T catalysts, yielding a maximum power density of 1000 mW m−2 when employed as air cathode MFCs. The significantly enhanced ORR performance of Cu/Co-NC@mS-800 could be attributed to following aspects: a) highly dispersed small CuCo nanoalloy particles, improved mesoporous surface area and volume owing to mSiO2 protection; (b) the formation of concave regular dodecahedron mesoporous structure with thin graphtic carbon layer as support; (c) the synergetic effect between CuCo nanoalloys. This work provides a facile strategy for the preparation of highly dispersed bimetal nanoalloys with enhanced electrocatalytic performance for energy-related applications.

High‐Entropy Zeolitic Imidazolate Frameworks for Dynamic Hydrogen Isotope Separation

Entropy‐driven strategy enables the systematic design of complex systems by using entropy as a quantifiable design parameter for the degree of mixing. In this study, we present mixed‐linker zeolitic imidazolate frameworks (ZIFs), sod‐ZIF‐1 series, that features two types of six‐membered rings (6MRs) with aperture sizes of 3.4 Å and 1.7 Å. By adjusting the configurational entropy, the ratio of these 6MRs can be systematically controlled, which significantly influences adsorptive properties, particularly improving the H2 affinity about 3 times throughout the series. This results in the significant enhancement of retention times in dynamic separation of hydrogen isotopes (D2/H2), even over LNG liquefaction temperature. This approach to entropy‐driven pore engineering provides new opportunities for enhancing gas adsorption and separation processes.

High-Entropy Zeolitic Imidazolate Frameworks for Dynamic Hydrogen Isotope Separation.

Entropy-driven strategy enables the systematic design of complex systems by using entropy as a quantifiable design parameter for the degree of mixing. In this study, we present mixed-linker zeolitic imidazolate frameworks (ZIFs), sod-ZIF-1 series, that features two types of six-membered rings (6MRs) with aperture sizes of 3.4 Å and 1.7 Å. By adjusting the configurational entropy, the ratio of these 6MRs can be systematically controlled, which significantly influences adsorptive properties, particularly improving the H2 affinity about 3 times throughout the series. This results in the significant enhancement of retention times in dynamic separation of hydrogen isotopes (D2/H2), even over LNG liquefaction temperature. This approach to entropy-driven pore engineering provides new opportunities for enhancing gas adsorption and separation processes.

Feasible Preparation of Naphthalimide-Functionalized Zeolitic Imidazolate Framework-8 for Control, and Fluorescence Detection of Virus: Optimization of Model Study.

The onset of the coronavirus has highlighted the critical need to swift diagnostic techniques to identify the virus. Metal Organic Frameworks (MOFs) have attracted considerable attention in the field of sensing due to the remarkable characteristics. The present research examines the microwave preparation of naphthalimide-functionalized zeolitic imidazolate framework-8 (NI/ZIF-8) to the detection of coronavirus as a probe. The microwave synthesis approach facilitates an environmentally sustainable, and effective production of NI/ZIF-8. Characterization techniques have validated the material's high crystallinity and thermal behaviour. In order to enhance the performance of the probe, a 23 factorial model is implemented. This model facilitates the influences of control parameters, including NI/ZIF-8 dose, solution temperature, and buffer pH, on quenching response. The findings indicate the 27°C, pH 8.2, and a NI/ZIF-8 dose of 0.6mg/mL yields the maximum quenching response (83.21%). Additionally, it has been determined that photo electron transfer plays a significant role within the quenching process. The sensor demonstrated remarkable sensitivity to the COVID-19 RNA, achieving an exceptionally detection limit of 5.45 pM and a quick sense (20min), alongside a high detection selectivity of RNA. This project underscores the applicability of NI/ZIF-8 as an effective and eco-friendly sustainable substance for the rapid and accurate detection of RNA of COVID-19.

Dynamic Polymer/Metal-Organic Framework Hybrid Microcapsules for Self-Healing Anticorrosion Coatings.

An ideal microcapsule effectively preserves an active substance and can rapidly release it to elicit a self-healing anticorrosion effect. However, the development of highly efficient microcapsules remains a challenge. In this study, polymer/metal-organic framework hybrid microcapsules with dynamic properties were constructed as self-healing anticorrosion coatings. The shell of the microcapsule consisted of flexible polydopamine and a hard crystalline zeolitic imidazolate framework-8 (ZIF-8) layer. The corrosion inhibitor 8-hydroxyquinoline (8-HQ) was trapped in the microcapsules and remained unreleased because the ZIF-8 layer acted as a molecular sieve. When the coating was surrounded by an acidic environment, the ZIF-8 nanocrystals in the shell dissociated, followed by the release of 8-HQ. A dense protective layer was formed on the steel surface to suppress extensive corrosion propagation. The |Z|0.01Hz value of the self-healing coating increased from 1.9 × 104 Ω cm2 to 2.2 × 106 Ω cm2 within 48 h and remained at this level until 120 h post application. This value is 3 orders of magnitude higher than that of a pure epoxy coating under the same conditions. Compared with conventional coatings, the novel dynamic microcapsules enable the application of self-healing coatings that can withstand harsh acidic environments without human intervention.

Three-dimensional nanocomposites derived from combined metal organic frameworks doped with Ce, La, and Cu as a bifunctional electrocatalyst for supercapacitors and oxygen reduction reaction

Fabrication of a nanocomposite with a low-cost and efficient synthesis method instead of using electrocatalysts based on platinum metal has become one of the main challenges in energy storage devices and fuel cells. In this regard, a bifunctional electrocatalyst for supercapacitors and oxygen reduction reaction is fabricated and tested. The novelty of this study is the synthesis method and enhancement of the electrochemical characteristics of synthesized electrocatalysts. The core-shell method is used for the electrocatalyst's synthesis which uses Zeolitic Imidazolate Framework (ZIF)-8, ZIF-67, and Material Institute Lavoisiers (MIL)-101 for the fabrication of three types of electrocatalysts. In the following, to increase the characteristics such as conductivity and stability, doping of Copper (Cu), Cerium (Ce), and Lanthanum (La) are added to the nanocomposites. The Co@NC, CoZn@NC, and CoZn@FeNC prepared electrocatalysts are obtained from the pyrolyze process of La/ZIF-67, CeCu/ZIF-8@ La/ZIF-67, MIL-101@CeCu/ZIF-8/La/ZIF-67. The results indicated that the CoZn@NC electrocatalyst has the best performance in the oxygen reduction reaction (ORR) with an onset potential of 0.062 (V vs Ag/AgCl) and current density of −12.97 (mA/cm2) at a constant voltage of −1 V. Furthermore, the electron transfer number of CoZn@NC electrocatalyst for ORR was 3.64. The conducted Galvanostatic Charge-Discharge (GCD) tests demonstrated that the CoZn@NC electrode has the highest capacitance of 271.14 F/g. The outcomes showed that by the core-shell method, various properties of nanocomposites can be utilized to solve the weaknesses of catalysts by using proper metals. Moreover, the presence of Cu2+,Ce3+,La3+ improve the structural defects in the carbon matrix, the stability based on the chronoamperometry results, and the mass transfer. The study provides a perspective for future researches to fill the research gaps to obtain the new supercapacitors utilize on a large scale in the electronics industry.

Incorporation of Bimetallic Nanoparticles in Zeolitic Imidazolate Framework‐67 (ZIF‐67) for Use as a Catalyst for Ethanol Oxidation

AbstractRecently, direct ethanol fuel cells (DEFCs) have been attaining a crucial role in energy resources and transportable devices. Many of the researchers in DEFCs has begin to engage considerable focus due to their high electrocatalytic activity, enormous stability, portability, and inexpensive. In this study, we present an anchoring of bimetallic Pd‐Cu nanoparticles supported ZIF‐67 catalyst (Pd‐Cu@ZIF‐67) for high‐performance electro‐oxidation of ethanol for direct alcohol fuel cells (DAFCs) applications. Structural, morphological, and elemental composition of the proposed catalyst were examined by using UV–vis spectroscopy, XRD, FE‐SEM, and EDX. Further, the electrochemical properties of Pd‐Cu@ZIF‐67 catalyst for ethanol oxidation in basic media were explored by using various electrochemical techniques. According to the results, the suggested catalyst showed maximum ECSA (128.7 m2g−1), higher current density (894.06 mA cm−2), durability (750s), and improved long‐term stability (230 cycles) than the other controlled catalysts towards ethanol oxidation reaction. This enhanced of the Pd‐Cu@ZIF‐67 catalyst is to the synergistic effects of Pd‐Cu nanoparticles and outstanding support material (ZIF‐67). These findings highly suggest the Pd‐Cu@ZIF‐67 catalyst as an anodic potential material in fuel cell applications.

Adsorption of Methane–Nitrogen mixtures with flexible Zeolitic Imidazolate Framework-7 (ZIF-7)

ZIF–7 is a pressure–regulated flexible metal–organic framework with a notably lower admission pressure for CH4 relative to N2, making it highly-prospective for curbing fugitive emissions of methane. Here, the separation of CH4 from N2 by an improved variant of ZIF–7 was studied over a range of pressures, temperatures, and compositions using multiple complementary techniques. Pure gas adsorption isotherms measured from (283 to 323) K at up to 16 MPa reveal this variant of ZIF-7 exhibits 50–60 % higher adsorption capacities for both CH4 and N2 in the large–pore phase than previous ZIF–7 samples. Binary mixture adsorption isotherms from dynamic column breakthrough experiments were consistent with those predicted from pure–gas isotherms using Ideal Adsorbed Solution Theory. Methane uptake increased significantly when the pore phase transition pressure for the mixture was reached, while the uptake of nitrogen remained small. Consequently, the equilibrium CH4-over–N2 selectivity of ZIF-7 is always larger than 5.5 and can increase to around 9, significantly above that of conventional adsorbents. Further characterisation showed the rate of the adsorption on ZIF–7 initially decreases as the pore phase transition begins before it increases significantly. Raman spectra acquired at various pressures along the adsorption isotherms revealed changes in certain vibrational modes associated with the structural change. Collectively, these observations indicate that the conceptually simple gating mechanism often used to describe the pore phase transitions in ZIF-7 in fact depends on interactions between the guest molecules and the adsorbent framework that continue to operate once the material is in the large–pore state.