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The CO2 adsorption capacity and the CO2/N2 selectivity of a series of Supported Ionic Liquid-Phase adsorbents (SILPs), including the novel inversely structured SILP "Inverse SILPs", are thoroughly investigated. ZIF-8, ZIF-69 and ZIF-70 were involved as the solid matrix, while ILs, having tricyanomethanide (TCM) as an anion and alkyl-methylimidazolium of different alkyl chain lengths (C2, C6, C8) as a cation, were used as the liquid constituents of the SILPs. The ultimate target of the work was to ratify a few recently reported cases of enhanced CO2 absorptivity in ILs due to their incorporation in ZIFs and to corroborate phenomena of CO2/N2 selectivity improvements in ZIFs, due to the presence of ILs. This ambiguity originates from the vague assumption that the pores of the ZIF are filled with the IL phase, and the free pore volume of a SILP is almost zero. Yet, through the integration of theoretical predictions with N2 porosimetry analysis of an actual sample, it is suggested that a thin layer of IL covered the exterior surface of a ZIF crystal. This layer could act as an impermeable barrier for N2, inhibiting the gas molecules from reaching the empty cavities laying underneath the liquid film during porosimetry analysis. This consideration is based on the fact that the solubility of N2 in the IL is very low, and the diffusivity at 77 K is negligible. In this context, the observed result reflects an averaged adsorptivity of both the IL phase and the empty pores of the ZIF. Therefore, it is incorrect to attribute the adsorption capacity of the SILP solely to the mass of the IL that 'hypothetically' nests inside the pore cavities. In fact, the CO2 adsorption capacity of SILPs is always less than the average adsorptivity of an ideal ZIF/IL mixture, where the two phases do not interact. This reduction occurs because some ZIF pores may become inaccessible, particularly when the IL forms a layer on the pore walls, leaving only a small empty core accessible to CO2 molecules. Additionally, the IL layer masks the active sites on the ZIF's pore walls. It should also be noted that the CO2/N2 selectivity increases only when the ZIF's pores are completely filled with the IL phase. This is because ILs have a higher CO2/N2 selectivity compared to the bare ZIF. [ABSTRACT FROM AUTHOR]

This research endeavour aims to investigate the adsorptive separation of the branched chain (BCAA) and aromatic amino acids (AAA). Based on the different molecular sizes of BCAA and AAA, zeolitic imidazolate frameworks (ZIFs) with different pore structures were prepared by regulating the size of imidazole ligands. The structure and pore shape were characterized by Fourier transform infrared spectroscopy (FT‐IR), x‐ray diffraction (XRD), scanning electron microscope (SEM), and BET surface area (BET). The results indicated the successful synthesis of ZIF‐[Co(mIm)2], ZIF‐[Co(eIm)2], and ZIF‐[Co(pIm)2] with pore size distribution of 7.821, 6.943, and 9.394 Å, and particle size of these ZIFs was approximately 4 μm. ZIF‐[Co(eIm)2] was chosen as the optimal ZIFs for the separation of BCAA and AAA. The adsorption experiment was evaluated in the respective single and binary systems. The corresponding data in a single system demonstrated that ZIF‐[Co(eIm)2] showed good adsorption performance for BCAA and poor for AAA. Furthermore, the adsorption behaviour under experimental conditions conformed well to the pseudo‐second‐order kinetic model and Langmuir isotherm. ZIF‐[Co(eIm)2] had great separation ability for BCAA/AAA in their binary system. Finally, regeneration studies further manifested that ZIF‐[Co(eIm)2] exhibited fine reusability performance with adsorption efficiencies still higher than 70% after five cycles. This study exhibits a novel path for the design of adsorbents for efficient separation of BCAA/AAA. [ABSTRACT FROM AUTHOR]

[Display omitted] • CoS@NC/NCNT forms a network matrix structure as a separator coating that facilitates carrier transport. • NCNTs can better prevent the agglomeration of active sites compared to commercial CNTs. • NC can protect CoS active sites from catalyst poisoning. Lithium-sulfur batteries (LSBs), with their high theoretical energy density and specific capacity, are considered optimal candidates for next-generation energy storage systems. However, significant challenges remain in their cycle life and efficiency for practical applications, primarily due to the shuttle effect of lithium polysulfides (LiPSs) and the poor electrical conductivity of sulfur materials. The key to addressing these challenges lies in designing materials with excellent dispersion, good electrical conductivity, and high catalytic activity. In this work, we have designed and successfully synthesized a unique structural material consisting of in-situ grown cobalt sulfide nanoparticles embedded in zeolite imidazolate frameworks (ZIFs), which are derived from N -doped carbon wrapped around polypyrrole-derived N -doped carbon nanotubes (CoS@NC/NCNT). This design effectively mitigates the shuttle effect of lithium polysulfides (LiPSs) and enhances the conductivity of the material. As a result, batteries with CoS@NC/NCNT-modified separators achieved a high specific discharge capacity of 1518 mAh g−1 at 0.1 C. This work provides a reliable design strategy for synthesizing N -doped carbon nanotube/high-activity transition metal sulfide composite materials and opens new avenues for enhancing the modification and separation of high-performance lithium-sulfur batteries (LSBs). [ABSTRACT FROM AUTHOR]

Developing an OER electrocatalyst that combines high performance with low cost represents a crucial challenge to address for the widespread adoption and implementation of PEM water electrolyzers. The Ru-based catalyst has garnered significant interest owing to its cost-effectiveness and high activity, positioning it as one of the prime contenders to replace Ir-based catalysts. Nevertheless, Ru-based catalysts are easily corrupted by oxidation at high potential, leading to poor catalyst durability. In this work, we used a simple method to synthesize an electrode material which was a carbon framework-supported coralline RuCo alloy catalyst on the CC surface. The porous and highly conductive carbon framework in RuCo@C/CC effectively anchors the RuCo alloy, preventing its aggregation and detachment from the CC. And the carbon framework also facilitates enhanced mass and charge transfer processes, thereby greatly improving catalytic performance. Additionally, charge transfer and redistribution occur within the RuCo alloy, thereby efficiently reducing the activation energy barrier (via the AEM mechanism) of the OER, consequently enhancing OER performance. Therefore, RuCo@C/CC exhibits outstanding performance in acidic OER, achieving a current density of 10 mA/cm2 at a remarkably low overpotential of 200 mV, significantly surpassing commercial RuO 2 (which requires 280 mV), owing to its exceptional OER kinetics, while also demonstrating exceptional stability in practical PEMWE test. This research introduces a convenient route for creating a highly efficient and durable alloy electrocatalyst, showcasing its promise for Proton Exchange Membrane Water Electrolysis. • Charge transfer and redistribution within RuCo reduce the OER energy barrier. • Role of C skeleton in preventing RuCo shedding and enhancing mass and charge transfer. • RuCo@C/CC shows a low overpotential of 200 mV at η 10 , surpassing commercial RuO 2. [ABSTRACT FROM AUTHOR]

The oxygen reduction reaction (ORR), occurred at cathodes in fuel cells, eco-friendly energy-conversion system, requires efficient electrocatalysts to overcome sluggish reaction kinetics. In this work, to enhance the ORR performance by decreasing potentials, we developed carbonized zeolite-imidazolate frameworks (ZIF) containing Co atoms (Co–C). The final product is produced by two-step process including (i) the formation of ZIF with Co species, and (ii) carbonization of the ZIF using high temperature treatment. Morphological characterizations revealed that the Co–C has polygon-shaped ZIF-based materials with metallic Co particles wrapped by layered carbon structures. The amount of Co atoms is found to be ~ 4 wt%, possessing a large surface area of 718 m2/g. X-ray photoelectron spectroscopy measurements further supported the formation of sp2 carbon structures with N-doping. The Co–C products exhibit an efficient electrocatalytic ORR performance in alkaline media, with their onset and half-wave potentials as of 0.97 and 0.86 V, comparable to those of Pt/C. Furthermore, Co–C shows the excellent cyclic durability and stability against for methanol poisoning. Collectively, this system including Co-based active species on ZIF networks provides a promise route for the development of efficient ORR electrocatalysts. [ABSTRACT FROM AUTHOR]

Novel zeolitic imidazolate frameworks (ZIFs), classical subtypes of metal organic frameworks (MOFs), and nanostructures are electro-engineered onto carbon fiber (CF), leading to a unique freestanding electrochemical platform of budlike nano Zn-ZIFs decorated CF (BN-Zn-ZIFs/CF). The unique morphology, structure, and composition are characterized by electron microscopy and energy spectrum analysis. Notably, the BN-Zn-ZIFs/CF platform displays superb electrocatalysis towards the oxidation of isoeugenol with encouragingly low overpotential and high current response. The strong electrocatalytic oxidation capability of BN-Zn-ZIFs/CF makes it an excellent sensing platform for isoeugenol detection. BN-Zn-ZIFs/CF sensor exhibits high-performance isoeugenol sensing with an extremely low limit of detection (13 nM) and wide detection range (0.1–700 µM). Besides, the BN-Zn-ZIFs/CF sensor can greatly resist interference from common ions, major biomolecules, and some amino acids. Moreover, excellent reliability, stability, and practicality are obtained. Our work demonstrates that the as-prepared BN-Zn-ZIFs/CF can act as an high-performance electrochemical sensor for the isoeugenol detection, the well-developed ZIF nanocrystal-modified conductive substrates can be a unique platform for the efficient sensing of other molecules, and the electrochemical engineering strategy can be an effective method for the growing of fresh MOF nanocrystals at conductive substrates in various electrochemical applications. [ABSTRACT FROM AUTHOR]

Zeolitic Imidazole Frameworks (ZIFs) have recently appeared as a new class of nonporous materials featuring notable physicochemical properties. In particular, ZIFs with core-shell structures have drawn a great deal of attention from research communities owing to their unique features, including superior specific surface area, high porosity content, extraordinary thermal, chemical, and structural stability, feasible synthesis conditions in a mild reaction, and facile growth on external surfaces of core nanostructures. This growth facilitates the synthesis of core/shell hybrid materials, which contain both organic (2-MIM) and inorganic (metal nodes) groups. As a structural advantage, the core/shell configuration favorably promotes the potential implementation of ZIFs in various functional fields, e.g. catalysis, drug delivery, adsorption, separation, and purification applications. The current review investigates recent advances in synthesizing and applying ZIFs with core-shell structures. This research review is divided into four parts. The first part overviews synthesis methods for ZIFs and discusses these nanostructures’ structural and material characteristics. The second part summarizes recent achievements and findings on synthesizing different types of ZIFs featuring core-shell structures. In the third part, potential applications of these novel nanostructured materials are presented, and their features are summarized in the final part. [ABSTRACT FROM AUTHOR]

The assembly of carbon dots (CDs) and metal–organic frameworks (MOFs) into MOF@CDs composite materials is rapidly advancing in the field of nanoscience, driven by the potential to harness or enhance the advantages of both CDs and MOFs. However, the exploration of MOFs@CDs with controllable morphologies poses a considerable challenge. Herein, we present a universal synthetic strategy for zeolitic imidazolate frameworks (ZIFs)@CDs composite materials with tunable morphologies and solid-state fluorescence by modulating the surface structure of carbon dots and adjusting the reaction temperature. The assembly process of this strategy is mainly governed by the competitive coordination relationship between the surface functional groups of the carbon dots and the imidazole ligand and the zinc metal sources. Besides, the incorporation of ZIFs@CDs into sodium alginate (SA) to prepare a hydrogel (SA/ZIFs@CDs) effectively enabled the identification and adsorption of copper ions in which the 24-h adsorption capacity of SA/ZIF-L@CD1 at an initial Cu2+ concentration of 500 ppm could reach 200.53 mg g–1. Moreover, the hydrogels dressing after adsorption of Cu2+ could be used to resist the growth of Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). This work provides insights for further advancements in structural design and a deeper understanding of the assembly behavior of the MOFs. [ABSTRACT FROM AUTHOR]

Abstract Herein, metal–organic frameworks (MOFs) derived nanoflower-like based binary transition metal (Ni–Mn) are successfully fabricated by a simple synthesis method. The fabricated nanoflower-like structure displays a unique nanoflower-like architecture and internal porous channels constructed by MOF coated on CuO/CF/ZIFs (Cox·Zn1−xO) substrate, which is beneficial for the penetration of electrolyte and electron/ion transportation. The as-prepared CF/CuO/ZIFs (Cox·Zn1−xO)@BMOF(Ni–Mn) electrode materials present significant synergy among transition metal ions, contributing to enhanced electrochemical performances. The as-prepared CF/CuO/ZIFs (Cox·Zn1−xO)@BMOF(Ni–Mn) hybrid nanoflower-like display a high specific capacity of 1249.99 C g−1 at 1 A g−1 and the specific capacitance retention is about 91.74% after 5000 cycles. In addition, the as-assembled CF/CuO/ZIFs (Cox·Zn1−xO)@BMOF(Ni–Mn)//AC asymmetric supercapacitor (ASC) device exhibited a maximum energy density of 21.77 Wh·kg−1 at a power density of 799 W kg−1, and the capacity retention rate after 5000 charge and discharge cycles was 88.52%.

ZIFs of different morphologies were synthesized by different solvents. Three types of ZIFs with different morphologies, ZIF-M, ZIF-P, and ZIF-L, were prepared using anhydrous methanol, polyethylene glycol-400, and water as solvents, respectively. The morphologies of ZIF-M and ZIF-L are rhombic dodecahedron and blade-like, respectively. Wherein the ZIF-M sample using methanol as solvent has an unusual morphology of high internal specific surface and pore volume. The ZIFs were characterized by XRD, SEM, AAS, N2 adsorption isotherms, pore size distribution, and evaluated with S. aureus and E. coli to gain antibacterial activity. Using the determination of growth curves, plate counting method and circle of inhibition method, the results showed that ZIF-M like has high antibacterial properties for ZIF-L and ZIF-P. Folding and rupture of the cell walls of dead bacteria was found by measuring the SEM of the bacteria. ZIF-M has the largest specific surface area, better potential properties and highest Zn2+ release, which leads to the high antibacterial effect of ZIF-M. [ABSTRACT FROM AUTHOR]

Aggregation of filler particles during the formation of mixed matrix membranes is difficult to avoid when filler loadings exceed a 10–15 wt %. Such agglomeration usually leads to poor membrane performance. In this work, using a ZIF‐67 metal–organic framework (MOF) as filler along with surface modification of Ag4tz4 to improve processability and selective olefin adsorption, we demonstrate that highly loaded with a very low agglomeration degree membranes can be synthesized displaying unmatched separation selectivity (39) for C3H6/C3H8 mixtures and high permeability rates (99 Barrer), far surpassing previous reports in the literature. Through molecular dynamics simulation, the enhanced compatibility between ZIF‐67 and polymer matrix with adding Ag4tz4 was proven and the tendency in gas permeability and C3H6 selectivity in the mixed matrix membranes (MMMs) were well explained. More importantly, the membrane showed a wide range of pressure and temperature resistance, together with remarkable long‐term stability (>900 h). The modification method might help solve interface issues in MMMs and can be extended to the fabrication of other fillers to achieve high performance MMMs for gas separation. [ABSTRACT FROM AUTHOR]

With the intensification of ecological environment problems and the improvement of public awareness of ecological civilization construction, as well as the global warming and climate change caused by excess CO2 in the atmosphere, the problem of excessive CO2 emission has received extensive attention globally in recent years and researchers have focused their attention on the technology of CO2 capture, utilization and storage (CCUS). CO2 cycloaddition with epoxide, as an efficient approach to fix and convert CO2, can solve the environmental concerns and reduce the dependence on fossil fuels simultaneously, is a promising way for CO2 utilization. The CO2 cycloaddition process usually requires catalysts, and zeolite-like imidazolate frameworks (ZIFs) have received extensive attention as a novel and effective catalyst due to its unique physical and chemical properties. Many ZIFs based or derived catalysts with different structures and functions have been developed to achieve efficient catalysis of CO2 cycloaddition with epoxide. In addition, effects have been made to design suitable catalytic materials and reveal the process mechanism, thus promote the industrialization of the process. In this paper, the recent research progress in the use of ZIFs based or derived catalysts to catalyze this reaction is reviewed, with emphasis on the design, mechanism for the catalysis, as well as the challenges and future prospect for the catalytic system.

Five mini proteins mimicking uricase comprising 20, 40, 60, 80, and 100 amino acids were designed based on the conserved active site residues within the same dimer, using the crystal structure of tetrameric uricase from Arthrobacter globiformis (PDB ID: 2yzb) as a template. Based on molecular docking analysis, the smallest mini protein, mp20, shared similar residues to that of native uricase that formed hydrogen bonds with uric acid and was chosen for further studies. Although purified recombinant mp20 did not exhibit uricase activity, it showed specific binding towards uric acid and evinced excellent thermotolerance and structural stability at temperatures ranging from 10°C to 100°C, emulating its natural origin. To explore the potential of mp20 as a bioreceptor in uric acid sensing, mp20 was encapsulated within zeolitic imidazolate framework‐8 (mp20@ZIF‐8) followed by the modification on rGO‐screen printed electrode (rGO/SPCE) to maintain the structural stability. An irreversible anodic peak and increased semicircular arcs of the Nyquist plot with an increase of the analyte concentrations were observed by utilizing cyclic voltammetry and electrochemical impedance spectroscopy (EIS), suggesting the detection of uric acid occurred, which is based on substrate–mp20 interaction. [ABSTRACT FROM AUTHOR]

For the effective utilization of carbon resources, a facile and recyclable heterogeneous catalyst system with high reactivity and stability is urgently needed for chemical fixation of CO2. Herein, a micro/nanostructured ZIF-8/CeO2 composite was designed by direct surface-nucleated ZIF-8 nanoparticles on spindle-like CeO2. The ZIF-8 nanoparticles content of the ZIF-8/CeO2 composite could be tuned by the changing of reaction parameters, such as the molar ratio of reactants and the reaction time. The ZIF-8/CeO2 composite exhibits remarkably enhanced catalytic activity and superior reusability for cycloaddition reaction of CO2 and epoxide than its pure substance. The enhanced performance of ZIF-8/CeO2 composite should be attributed to its high specific surface area and abundant porosity, outstanding thermal stability, and the appearance of a new moderate acid/base site in composite material. Considering the convenient preparation, enhanced catalytic activity and excellent reusability of ZIF-8/CeO2 composite, this work offers a new strategy to replace ZIFs-based porous catalysts for chemical fixation of CO2. [ABSTRACT FROM AUTHOR]

As an emerging class of nanoporous materials, Metal Organic Framework (MOFs) are distinguished for environmental remediation. ZIFs and Ni-MOF chosen as fluoride (F-) scavengers due to their robust structures and straightforward synthesis routes. F- adsorption was studied as a function of the ZIFs geometry and structural properties. The efficacy of MOFs for F- abatement was in the order of ZIF-67-NO3 (70.1%) > ZIF-8-Cube (64.7%) > ZIF-67-OAc (62.4%) > ZIF-8-Cuboid (59.2) > Ni-MOF (58.5%) > ZIF-8-Octahedron (57.1%) > ZIF-8-Leaf (55.3%) > ZIF-67-SO4 (55.1%) > and ZIF-67-Cl (52.3%). The key operating variables i.e. pH, mixing time, F- concentration, and ZIF-67-NO3 dose were modeled using the Box-Behnken design (BBD). The model revealed the process mainly influenced by solution pH. The model optimized the operating condition and obtained a maximum 85.9% F- removal by mixing time = 41.1 min, ZIF-67-NO3 dose = 0.9 g/L, solution pH = 4.86, and F- = 6.5 mg/L. Non-linear form of isotherm and kinetic models disclosed the multilayers F- adsorption onto ZIF-67-NO3 with an qmax =25.9 mg/g, and chemisorption as the rate-controlling step. F- sorption decreased slightly by temperature in the range of 303 to 323 K. The structure of ZIF-67-NO3 remained stable under three consecutive use-reuse cycles with an about 10% loss in removal efficiency.

Several ZIFs and their functionalised derivatives have been reported as efficient catalytic materials for the fixation of CO2 in the bid to reduce global warming, caused by the persistent use of fossil fuels. However, the major challenge of using these ZIFs at large scales requires the scalability of their synthesis. Herein, a series of Zn-based zeolite imidazolate frameworks (ML-ZIFs) with mixed linkers (2-methylimidazole and 2-nitroimidazole) were synthesised via an easily scalable procedure. The products were characterised by PXRD, TGA, TEM, N2 isotherms, digestive 1H NMR and evaluated as catalysts for CO2 fixation. All ML-ZIFs are thermally stable, highly porous with SOD or frl topologies and particle sizes of 44–360 nm. ML-ZIF 3 with [Zn(mIm)0.87(nIm)1.13] composition resulted in the highest CO2 uptake of 91 cm3g−1. ML-ZIF 4 (Zn(mIm)1.44(nIm)0.56) led to the highest catalytic activity (684 h−1) by a ZIF derivative in the cycloaddition of CO2 to epichlorohydrin substrate. [ABSTRACT FROM AUTHOR]

MOFs (Metal–Organic Frameworks) are so-called coordination polymers with a porous crystalline structure. In this review, the main emphasis was placed on these compounds' use in modifying titanium implants. The article describes what MOFs are, gives examples of ligands used in the synthesis of MOFs, and describes a subgroup of these materials, i.e., Zeolitic imidazolate frameworks. The article also lists the basic biomedical applications of these compounds. This review shows the significant impact of titanium surface modification with Metal–Organic Frameworks. These modifications make it possible to obtain layers with antibacterial properties, better corrosion resistance, increasing cell proliferation, faster bone growth in vivo, and much more. The presented work shows that the modification of titanium with MOFs is a very promising method of improving their properties. We hope that the prepared review will help research groups from around the world in the preparation of implants modified with Metal–Organic Frameworks with enhanced properties and utility applications. [ABSTRACT FROM AUTHOR]

Developing highly active and stable non-noble metal bifunctional electrocatalysts are urgently demanded in overall water splitting. Herein, tunable precursor ratio synthesis of cobalt-based ZIFs as a template derived active cobalt embedded N-doped carbon (Co@NC) catalyst. The rational synthesis of ZIF templates significantly impacts the complex nanostructure and properties of the catalyst (Co@NC). Consequently, the different nanostructures on Co@NC exhibit significance for the electrocatalyst of hydrogen and oxygen evolution reactions. The optimized Co@NC-20 provides excellent electrocatalytic activity with the lowest overpotential of 172 and 301 mV for HER and OER, respectively, at the current density of 10 mA cm−2. The bifunctional Co@NC-20 reveals a potential for overall water splitting as low as 1.68 V of 10 mA cm−2. After continuously working for 24h, the exceptional stability activity maintains 75% of the catalytic performance on Co@NC-20. The beneficial character in the synergistic effects between high-active Co species with well-protection of the metal core by carbon shell promotes their excellent performance. This study provides an essential reference for the rational design of ZIF templates for electrocatalysts with more complex structures in the future. [Display omitted] • Rational fabrication Co-ZIF template for sacrificial into Co@NC. • Ratio precursors (M:L) impact in structure/morphologies Co-ZIF template. • High efficient Co@NC electrocatalysts of OER/HER for water splitting reaction. • High active Co/N species for superior bifunctional electrocatalytic performance. • The carbon shell's well-protected core active site indicates good long-time stability features. [ABSTRACT FROM AUTHOR]

Mixed matrix membranes (MMMs) combine the high separation performance of porous materials with the processibility of polymers and so possess potential for carbon capture from CO 2 -containing gas streams. Zeolitic imidazolate frameworks (ZIFs) are promising candidates as molecular-sieve fillers in MMMs due to their tunability and ease of synthesis. We have compared four ZIFs, all as nanoparticles of similar sizes (ca. 400 nm), as MMM fillers, to investigate the effects of ZIF structure and chemistry on MMM performance of pure gas (CO 2 , N 2) permeation under the same conditions. The chosen ZIFs include two that exhibit strong CO 2 adsorption (hybrid ZIF-7/COK-17 and ZIF-94) and two that have higher pore volumes but weaker CO 2 interactions (ZIF-8 and a hybrid ZIF-11/ZIF-71). The hybrid ZIF-7/COK-17 and ZIF-94 are structurally related to ZIF-7 (rhombohedral sod topology) and ZIF-8 (cubic sod), respectively, via partial or complete substitution of benzimidazole or 2-methylimidazole by 4,5-dichloroimidazole or 4-methyl-5-imidazolecarboxaldehyde, while the hybrid ZIF-11/ZIF-71 has the rho topology but the same composition as the ZIF-7/COK-17 hybrid. In the first part of the comparative study, MMMs based on two types of commercial polymers, Matrimid®5218 and PEBAX-MH1657, were prepared containing the ZIF-7/COK-17 hybrid and also with ZIF-94. ZIF-94 shows much better compatibility with the polymers, forming homogeneous dispersions at all loadings attempted (≤35 % wt%) whereas the hybrid shows inhomogeneity above 12 wt% in each case. At 12 wt% loading, both fillers show an increase in CO 2 permeability at 1.2 bar and 293 K compared to the pure membrane (in PEBAX, this increases from 49.5 to 60 and 68 Barrer) which is the result of increased solubility compensating for decreased diffusivity, and this improvement in permeability continues to increase at the higher levels of loading possible with ZIF-94. ZIF-7/COK-17 in PEBAX show higher selectivity, achieving a calculated CO 2 /N 2 selectivity up to 70. Further investigation of CO 2 and N 2 permeation on MMMs with the four ZIFs at 12 wt% in PEBAX-MH1657 showed a clear distinction between the ZIF-94 and ZIF-7/COK-17 MMMs (which show higher membrane solubilities but lower diffusivities) compared to ZIF-8 and ZIF-11/ZIF-71 MMMs. At the loading chosen, the CO 2 permeability increase achieved by the four ZIFs over PEBAX-MH1657 increases in the order ZIF-11/-71, ZIF-7-COK-17 (ca. 60 Barrer) < ZIF-94 (68) < ZIF-8 (81), reflecting the complex interplay between CO 2 solubility (increasing with interaction strength) and diffusivity (increasing with available cage and window size). The calculated CO 2 /N 2 selectivity is highest for the hybrid ZIF-7/COK-17 membrane (70), which is attributed to molecular sieving effects in the rhombohedral sod structure. [ABSTRACT FROM AUTHOR]

Zeolitic Imidazolate (metal organic) Frameworks (ZIFs) and Prussian Blue Analogues (PBAs) are promising materials in electrochemical sensing due to their unique properties. In this study, a composite material comprising NiFe-PBA and ZIF-67 was synthesized and made to form a uniform layer onto a glassy carbon electrode (GCE) to enhance electrochemical performance for furazolidone (FZD) detection. The synthesized NiFe-PBA/ZIF-67 composite exhibited excellent sensitivity, selectivity, and stability towards FZD detection, with a low limit of detection (LOD). The electrochemical behaviour of FZD on the NiFe-PBA/ZIF-67/GCE electrode was investigated, revealing a diffusion-controlled process. Differential pulse voltammetry (DPV) analysis demonstrated the synergetic effect of the PBA/MOF core-shell structure in enhancing FZD electro-reduction. The sensor exhibited exceptional LOD of 0.007 μM. Selectivity studies confirmed the sensor's ability to distinguish FZD from potential interferents. Extensive evaluations demonstrated the sensor's reproducibility, repeatability, and long-term stability, affirming its practical utility. Real sample analysis further validated the sensor's excellent analytical capabilities in diverse matrices. [Display omitted] • A novel core-shell structured MOF embedded Prussian Blue Analogues was designed for the electrochemical detection of an antibiotic drug. • The development of such sensors showed excellent electrochemical performances which will help in reducing environmental pollution. • The NiFe-PBA/ZIF-67 composite showed a lower LOD of about 7 nM. • The sensor's real-world utilization was highly appreciable with excellent selectivity, stability, repeatability, and reproducible behavior. • Thus, the NiFe-PBA/ZIF-67 stands as a promising electrode material for monitoring the environmental pollutant furazolidone. [ABSTRACT FROM AUTHOR]

Co@hollow carbon nanofibers (Co@HCNFs) catalysts with multi-level pore structures were fabricated by coaxial electrospinning, in-situ growth of ZIF-67 and subsequent high temperature pyrolysis. The as-prepared Co@HCNFs-0.6–0.1 catalyst exhibits superior catalytic performance in the CO 2 cycloaddition with epichlorohydrin in the absence of a co-catalyst, achieving super high specific activity of 838 mmol⋅min−1⋅g−1. [Display omitted] • Co@hollow carbon nanofibers with multi-level pore structures were fabricated. • Many Co@CN nanoparticles are uniformly distributed within the carbon nanofibers. • The multi-level pore structures provide more paths for the mass transfer. • Many well-distributed Co@CN nanoparticles provide more catalytic sites. • Co@HCNFs-0.6–0.1 has superior catalytic performance for the CO 2 cycloaddition. In pursuit of carbon neutrality, the development of highly efficient catalysts for the CO 2 cycloaddition with epoxides represents a prominent approach of utilizing CO 2 to produce valuable cyclic carbonates. Herein, Co@hollow carbon nanofibers (Co@HCNFs) catalysts with multi-level pore structures were fabricated by coaxial electrospinning, in-situ growth of zeolitic imidazolate framework-67 (ZIF-67) and subsequent high temperature pyrolysis. The hollow structure and the formation of the active sites of Co@N-doped carbon (Co@CN) were regulated by changing the feeding ratio of core to shell and the Co(NO 3) 2 ·6H 2 O concentration during the ZIF-67 growth, thereby fine-tuning the catalyst structures and its catalytic performance. The as-prepared Co@HCNFs-0.6–0.1 catalyst exhibits superior catalytic performance in the CO 2 cycloaddition and epichlorohydrin without a co-catalyst, achieving superior specific activity of 838 mmol⋅min−1⋅g−1. The outstanding catalytic performance is attributed to its multi-level pore structures with rich N content and well-distributed Co@CN nanoparticles. Moreover, Co@HCNFs-0.6–0.1 exhibits good stability over ten reaction cycles. [ABSTRACT FROM AUTHOR]

One way to exploit CO2 is to use it as a feedstock for the production of cyclic carbonates via its reaction with organic epoxides. As far as we know, there is still no heterogeneous catalyst that accelerates the reaction in a selective, efficient and industrially usable way. Cobalt and zinc-based zeolitic imidazole frameworks (ZIFs) have been explored as heterogeneous catalysts for this reaction. In particular, we have prepared ZIF-8 and ZIF-67 catalysts, which have been modified by partial replacement of 2-methylimidazole by 1,2,4-triazole, in order to introduce uncoordinated nitrogen groups with the metal. The catalysts have shown very good catalytic performance, within the best of the heterogeneous catalysts tested in the cycloaddition of CO2 with epichlorohydrin. The catalytic activity is due ultimately to defects on the outer surface of the crystal, and varies in the order of ZIF-67-m > ZIF-67 > ZiF-8-m = ZIF-8. Notably, reactions take place under mild reaction conditions and without the use of co-catalysts. [ABSTRACT FROM AUTHOR]

Fe-N-doped carbon (Fe-N-C)-based electrocatalysts are considered to be promising alternatives to replace Pt-based catalysts for oxygen reduction reactions (ORR). Here, we reported a simple and effective approach to prepare Fe-N-C-based electrocatalysts with the shape of two-dimensional nanosheets (termed Fe/NCNSs) to enhance the ORR performance. Fe/NCNSs were prepared by the calcination of Fe/Zn dual-metal ZIFs nanosheets as precursors. Benefiting from its higher specific surface area, electrochemically active surface area, and proportion of pyridinic N and Fe-N, the optimized Fe/NCNS showed excellent ORR performance both in acidic (E1/2 = 0.725 V vs. RHE) and alkaline (E1/2 = 0.865 vs. RHE) media, being 23 mV more negative and 24 mV more positive than that of a commercial Pt/C. The optimized Fe/NCNS also exhibited long durability. In addition, the Zn-air battery with Fe/NCNS-1 and RuO2 as the air catalyst exhibited high power density (1590 mW cm−2 at a current density of 2250 mA cm−2) and superior charging/discharging durability. [ABSTRACT FROM AUTHOR]

Herein, a core–shell structured zeolitic imidazolate framework (ZIF)‐90@ZIF‐67 is successfully synthesized with higher specific area and more micropores by a seed epitaxial growth method at room temperature, combining both the advantages of ZIFs and core–shell‐structured materials. When it is applied for supercapacitors' electrode materials, ZIF‐90@ZIF‐67 delivers the best energy storage ability and excellent electrochemical stability. In a three‐electrode system, its specific capacitance reaches 1357.8 F g−1 at 1 A g−1 and maintains 55.4% while increasing the current density from 1 A g−1 to 20 A g−1. In a two‐electrode system, an all‐solid‐state asymmetric supercapacitor is assembled using ZIF‐90@ZIF‐67 and activated carbon (CV) as the positive and negative electrode material. The simple device exhibits a high specific capacitance of 151.6 F g−1 at 0.5 A g−1 and a high energy density of 53.9 Wh kg−1 at 510.2 W kg−1. Surprisingly, the device achieves a specific capacitance retention of 95.8% after 10 000 cycles at 10 A g−1. Finally, two simple all‐solid‐state supercapacitors in series power a blue lighting‐emitting diode for over 13 min, which reveals that the core–shell ZIF‐90@ZIF‐67 has great potential application prospects in the field of energy storage. [ABSTRACT FROM AUTHOR]

Rational design and tailoring of the structural features of Co—N—C catalysts are urgently required to construct highly efficient bifunctional non-noble metal electrocatalysts for both oxygen evolution reaction (OER) and oxygen reduction reaction (ORR). Herein, we report a series of carbon-based catalysts with varied structural features, specifically the graphitic degree of carbon, porosity, and the configuration of active sites, and their effects on bifunctional oxygen electrocatalytic reactions. Through the synergistic tuning of these structural factors, the well-tailored Co—N—C catalyst exhibits a high bifunctional electrocatalytic activity, as revealed by a half-wave potential of 0.84 V for ORR and a low overpotential of 420 mV at 10 mA·cm−2 for OER. More impressively, the Zn-air battery using the optimum catalyst delivers excellent performance including a peak power density of 125.2 mW·cm−2 and a specific capacity of 790.8 mAh·gZn−1, as well as stable cycling durability, outperforming the noble metals-based catalysts. The first-principles calculations reveal that the interlayer interaction between the pyridinic N-doped graphene and the confined Co nanoparticles increases the electronic states of the active C atoms near the Fermi level, thus enhancing the adsorption of the HOO* intermediate and generating superior catalytic activity for bifunctional oxygen electrocatalysis. By comprehensively studying the structural factors of catalysts, the bifunctional catalytic behaviors, the use in a practical Zn-air device, and theoretical simulations, this work may also give inspirations to the design, use, and understanding of other kinds of catalysts. [ABSTRACT FROM AUTHOR]

In the field of catalysis, nanoreactors with spatially restricted effects play a critical role to enhance the production efficiency of a variety of reactions. In this contribution, we used ZIF-67 nanocubes (size of 140 nm) as a template and conformally deposited Al2O3 thin films by the atomic layer deposition (ALD) technique, wherein Pt nanoparticles (Pt NPs) as active sites were loaded on either the inside or outside of the Al2O3 films. Notably, it was found that the water treatment of the nanoreactors was critical to the enhanced catalytic CO oxidation performance with substantially decreased T100 (temperature to achieve 100% conversion). Various characterization results indicated the successful synthesis of yolk–shell structured ZIF-67/Pt@10Al2O3-W catalyst with excellent CO oxidation activity and good long-term stability. In addition, in situ diffuse reflectance infrared Fourier transform spectroscopy was used to explore the catalytic oxidation process, and the results revealed that the reason for the superior CO catalytic activity of the designed nanoreactors was ascribed to the moderate CO surface coverage provided by the Al2O3 films and the activated oxygen species. In summary, this work provides some insights into the preparation of metal–organic framework-based nanoreactors using ALD-assisted methods. [ABSTRACT FROM AUTHOR]

This work presents the use of encapsulated mini protein 20 mimicking uricase (mp20)-zeolitic imidazolate framework-8 (ZIF-8) as a bioreceptor for the development of a nanozyme-based electrochemical biosensor for uric acid detection. The electrochemical performance of the biofunctionalized mp20@ZIF-8 on the reduced graphene oxide/screen-printed carbon electrode (rGO/SPCE) was investigated by optimizing operating parameters such as pH, deposition potential, and deposition time using a central composite design-response surface methodology (CCD-RSM). The quadratic regression model was developed to correlate the combination of each variable to the oxidation current density as a response. A significant effect on current response was observed under optimized conditions of pH of 7.4 at −0.35 V deposition potential and 56.56 s deposition time, with p < 0.05 for each interacted factor. The obtained coefficient of determination (R2) value of 0.9992 indicated good agreement with the experimental finding. The developed nanozyme biosensor (mp20@ZIF-8/rGO/SPCE) exhibited high selectivity in the presence of the same fold concentration of interfering species with a detection limit of 0.27 μM, over a concentration range of 1 to 34 μM. The practicality of the tailored biosensor in monitoring uric acid in human serum and urine samples was validated with high-performance liquid chromatography (HPLC) and a commercial uric acid meter. Hence, nanozyme-based is a promising platform that offers a rapid, sensitive, selective, and low-cost biosensor for the non-enzymatic detection of uric acid in biological samples. [ABSTRACT FROM AUTHOR]

Zeolite imidazolate frameworks (ZIFs) are a subclass of metal–organic frameworks (MOFs) containing N element, which are always exploited to prepare N-incorporated carbon materials containing rich carbon nanotubes (CNTs) via the pyrolysis. Humic acid layers are regarded as a natural GO-like material due to similar laminate size and thickness, physical and chemical structures, surface polarity, and activity to graphene oxide (GO). Here, a layered humate-ZIF (HA-CoFe-ZIF) composite template is elaborately designed and first constructed by a hydrothermal method using sodium humate as the substrate. An N-incorporated carbon skeleton (NCS) support assembled by CNTs and graphene layers is then achieved after the segmented pyrolysis and acid etching. Afterwards, a PtCoFe/NCS electrocatalyst with high catalytic activity and cycling stability for methanol oxidation reaction (MOR) is purposefully synthesized by loading PtCoFe nanoparticles on the NCS surface via ethylene glycol-sodium borohydride (EG-NaBH4) double reduction. The supported catalyst constructs a composite structure with good dispersibility of metal nanoparticles on the NCS surface due to the oriented coordination bonding between metal and nitrogen incorporated in the NCS. The large specific surface and good electrical conductivity of the NCS support together guarantee high MOR electrocatalytic activity, stability, and CO tolerance ability of PtCoFe nanoparticles. [ABSTRACT FROM AUTHOR]

[Display omitted] • CF/ZIF-7-NH 2 is acquired through an in-site self-assemble strategy. • CF/ZIF-7-NH 2 enables ultrarapid adsorption for Hg(II) with h of 38.26 mg g−1 min−1. • CF/ZIF-7-NH 2 exhibits outstanding adsorption capacity of 909.09 mg g−1 for Hg(II). • The active and abundant O − and N − sites are responsible for Hg(II) adsorption. Adsorptive removal of mercury ion from wastewater has become a hot topic due to the toxicity and persistence; acquiring adsorbent materials with high-capacity, rapid-kinetic, super-selective while low-cost features are highly demanded. Herein, based on the full functionality of collagen fiber (CF) from the leather waste, we proposed an innovative synthetic approach through exploiting amino-functionalized ZIF-7 (ZIF-7-NH 2) as functional groups to facilely in-situ incorporate with CF, affording low-cost but effective adsorbent materials of CF/ZIF-7-NH 2 composite maximizing both functions of CF and ZIF-7-NH 2 in the Hg(II) capture. Remarkably, it exhibits an ultra-high capacity as high as 909.09 mg g-1, fast kinetics that could remove 99.01 % of 200 mg·L-1 within 20 min, and significant selectivity of S Hg/M (K d Hg / K d M) as large as 522–1017 over Mg2+, K+, Ca2+, Cd2+, and Mn2+. We understand such an impressive adsorption is contributed by the synergistic action between functional groups including on the CF and ZIF-7-NH 2. This study offers an effective method for removing heavy metal ions, achieving efficient removal of Hg(II) ions for pollution control, and promoting the reuse of waste CF to reduce waste accumulation in various aspects. [ABSTRACT FROM AUTHOR]

• The optimized Fe, Cu co-doped ZIF-derived N -doped carbon (FeCu 0.28 -NC) are prepared. • FeCu 0.28 -NC shows a half-wave potential of 0.925 V in 0.1 M KOH for oxygen reduction. • FeCu 0.28 -NC shows good oxygen evolution performance. • Zinc-air batteries show a high-power density of 85 mW cm−2 at 140 mA cm−2. Zinc-air batteries (ZABs) have attracted attention for their environmental friendliness, durability, safety and high energy density. The superior performance of rechargeable ZABs hinges on the activity of oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). Here, we successfully develop a Fe, Cu co-doped ZIF-derived N-doped carbon (FeCu x -NC) catalyst, featuring a lamellar "red blood cell" structure. In the ORR process, the optimized FeCu x -NC catalyst achieves a half-wave potential of 0.925 V under alkaline conditions, 70 mV higher than commercial Pt/C catalysts, and exhibits good stability. In the OER process, at 10 mA cm−2, the overpotential is measured at 510 mV and the Tafel slope value is 55.2 mV dec−1. When utilizing optimized FeCu x -NC catalyst without RuO 2 at a catalyst loading of 2 mg cm−1, the assembled ZABs demonstrate a power density of 85 mW cm−2 at 140 mA cm−2, while maintaining excellent cycling stability (with only a 0.11 V increase in the voltage interval between charging and discharging over 300 cycles), thereby realizing the dual function of ORR/OER. [ABSTRACT FROM AUTHOR]

ZIF-8 and ZIF-67 are two highly similar Zeolite iminazolate frameworks (ZIFs) materials. In the field of adsorption, ZIF-8 is more suitable than ZIF-67 in most cases. In the field of catalysis involving electron transfer, ZIF-67 is more reliable. Using these two materials for modification and activation of peroxymonosulfate (PMS), ZIF-67 is a cobalt based metal catalyst, while ZIF-8 volatilizes the zinc node at a calcination temperature above 800 ℃, thereby transforming into a non-metallic catalyst. Generally speaking, ZIF-67 derivatives have better activation effects, while ZIF-8 derivatives have less metal leaching and no concerns about secondary pollution. In addition, some researchers have combined ZIF-8 with ZIF-67 in the hope of combining their advantages. These three types of materials can generate a large number of free radicals and non - radicals by activating PMS, achieving the effect of degrading pollutants. [Display omitted] • Different performances of ZIF-8 and ZIF-67 were illustrated. • The latest progress in improving PMS activation by ZIF-8 and ZIF-67 derivatives. • The advantages and disadvantages of metal catalysts and non-metal catalysts. • Prospects for future research on zinc-cobalt synergistic activation of PMS in AOPs. Zeolite imidazolate frameworks materials (ZIFs, especially ZIF-8 and ZIF-67) used as catalysts for peroxymonosulfate (PMS) activation to generate reactive oxidative species (ROS), such as free radicals and singlet oxygen radicals, for the degradation of organic pollutants in the advanced oxidation processes (AOPs) have received much attention recently. The synthesis and modification methods of ZIF-8 and ZIF-67 were introduced in detail, particularly based on the specificity generated by the differences in the characteristics of the material itself. In additional, the modification of ZIF-8/ZIF-67 composites for activating PMS was systematically discussed for the first time. The feasibility and possible development directions of zinc-cobalt co-catalysis were proposed. Finally, the potential active sites of modified materials in the catalytic process were summarized, the degradation mechanism were elucidated, and the difficulties and challenges that ZIFs still need to face in activating PMS in the future were explained. [ABSTRACT FROM AUTHOR]

The heterometal functionalization on zeolitic-imidazole frameworks (ZIFs) is a strategy to modify properties over the homometal ZIFs. A green strategy for simultaneously functionalized iron atoms during the crystal formation of ZIF-67 (Fe@ZIF-67) through the solid-solid thermal (SST) method is newly developed. The single-step process and absent solvent conditions are beneficial advantages of this SST method over the early reported synthetic methods. The results show that the iron is well-dispersed and homogeneously coordinated in the structure of Fe@ZIF-67. Moreover, the optimal iron-functionalized ZIF-67 (20Fe@ZIF-67) significantly enhances the catalytic performance of CO 2 cycloaddition epoxide by 2.3 times compared to pristine ZIF-67 under mild reaction conditions. The DFT calculation reveals that the iron atom induces the unsaturated sites or defect structure on the Fe@ZIF-67 catalyst, providing more reactive sites for the catalytic activity of the reaction. [Display omitted] • The green strategy of solid-state thermal (SST) method functionalizes iron atoms into ZIF-67 (Fe@ZIF-67). • Single-step under solvent-free and mild conditions are advantages of the SST method. • Iron atoms are randomly dispersed and homogeneously distributed on the obtained Fe@ZIF-67. • Distinctive contributions of hetero-iron in Fe@ZIF-67 play a pivotal role in the catalytic performance. • The Fe atom reveals high binding energy and plays a role in excellent catalytic activity on Fe@ZIF-67. [ABSTRACT FROM AUTHOR]

A high-efficiency adsorbent ZIF-8 was successfully prepared in a microemulsion system provided by an ionic liquid, which showed excellent potential for removing phosphate from water. The properties of the adsorbents were determined by several characterization methods, such as X-ray diffraction (XRD), infrared spectroscopy (FTIR) and Brunauere-Emmette-Teller (BET) et al. The results confirmed that ZIF-8 prepared in the ionic liquid microemulsion (ZIF-8-ILM) has a smaller particle size compared with that prepared in an aqueous solution. Moreover, the ZIF-8-ILM holds a high BET specific surface area and pore volume, as well as the textural meso- and macro-porosities formed by inter-particle voids. Based on these traits, the ZIF-8-ILM exhibit excellent adsorption capacity for phosphate, as evidenced by a maximum adsorption capacity of 178.99 mg/g was obtained. In addition, the capture of phosphate on ZIF-8-ILM was quite quickly and reached equilibrium within 60 min. A high-efficiency adsorbent ZIF-8 was successfully prepared in a microemulsion system provided by an ionic liquid. The ZIF-8 materials prepared not only had high BET specific surface area and pore volume but also exhibited hierarchical pore structure, which showed excellent potential for removing phosphate from water. [ABSTRACT FROM AUTHOR]

Zeolitic imidazolate frameworks (ZIFs) consist of transition metal ions (Zinc or Cobalt) and imidazolate (Im) linkers in tetrahedral coordination surrounded by nitrogen atoms from the five-membered imidazole ring serving as a bridging linker, i.e. a link connecting the metal centres in the three-dimensional framework. The crystal structures of ZIFs share the same topologies as those that can be found in aluminosilicate zeolites. ZIFs have advantages over zeolites such that the hybrid framework structures are expected to have more flexibility in surface modification. Due to their interesting properties such as high porosity, high surface area, exceptional thermal and chemical stability, ZIFs are very attractive materials with potential applications including gas sorption, gas separation, and catalysis. Over a decade tremendous work has been carried out to develop ZIFs in synthesis and its various applications. In this review, we have briefly composed the different methods for the synthesis of ZIFs such as solvent-based and solvent-free methods. In addition, its thermal and chemical properties and potential applications in the field of adsorption, separation, catalysis, sensing, and drug delivery have been summarized. [ABSTRACT FROM AUTHOR]

The photocatalytic properties of Zn/Co zeolite imidazolate frameworks (ZIF-ZnCo) prepared by various Zn/Co ratio are of significantly diversity due to the morphology structure of the ZIF-ZnCo. Thereinto, the prepared ZIF-ZnCO-8:1 is excellent capability by virtue of its 3D cross-shaped structure. Spectral test results show that as-prepared novel 3D cross-shaped ZIF-ZnCo has a lower recombination rate of electron and hole pairs than the lamellar and dodecahedral, thus improving the photocatalytic ability. The photocatalytic ability of 3D cross-shaped ZIF-ZnCo was carefully investigated for removing mixed solution of Congo Red (CR) and Cr(VI). The photocatalytic reduction ability of 3D cross-shaped ZIF-ZnCo was 22% higher than ZIF-8 for Cr(VI). Meanwhile, CR was altogether removed at dark processing and Cr(VI) was removed 70% after dark processing 120 min and photocatalytic 240 min. Therefore, the high adsorption and photocatalytic capacity denote the potential application of 3D cross-shaped ZIF-ZnCo. [ABSTRACT FROM AUTHOR]

Nitrogen-doped porous carbon material was generated via thermal pyrolysis of zeolitic imidazole frameworks (ZIFs). The structure of the ZIF templates was tuned, so that the obtained product was an N-doped porous carbon-containing encapsulated metal nanoparticle. The hierarchical structural and unique properties of pyrolyzed materials are involved in further application, including catalysis. The as-synthesized porous carbon materials were applied as a catalyst for CO2 fixation on cyclic carbonates under near ambient pressure without solvent and co-catalyst. The zinc dispersion in highly porous carbon material, deriving from ZIF-8, exhibited a superior catalytic performance among the synthesized materials. The acid sites (Zn species) and the incorporated basic sites (N-species) present in the porous carbon material are essential for a high affinity for gas adsorption and CO2 conversion. Additionally, the catalyst was found to be very robust and stable during recycling studies as the catalytic performance remained high for seven cycles. [ABSTRACT FROM AUTHOR]

In this study, a series of Ni-based Zeolitic Imidazolate Framework (ZIF) is successfully co-precipitated at room temperature with different ratios of nickel (II) nitrate hexahydrate (Ni(NO3)2⋅6H2O) to 2-methylimidazole (mIM) at different ratios of 3:10, 1:1, and 10:3, denoted as Ni-ZIF-1, Ni-ZIF-2, and Ni-ZIF-3. The morphology, elemental, and structural investigation of Ni-ZIFs are carried out using field emission scanning electron microscopy (FESEM), energy-dispersive X-Ray spectroscopy (EDX), Fourier transform infrared (FTIR) spectroscopy, and X-ray diffraction (XRD). The electrochemical performance reveals that the Ni-ZIF-3 successfully delivered the highest specific capacitance of 433 F g−1 at current density of 0.25 A g−1. It is important to note that when Ni-ZIF-3 is used in carbon asymmetric supercapacitor (ASC), the specific capacitance of 85 F g−1 is achieved at a current density of 0.25 A g−1, whilst maintaining outstanding cycling stability of 93% after 1500 cycles at reversible current density from 0.5 A g−1 until 1.0 A g−1. A little decay during the cycle test demonstrates that the device is capable of offering durable devices with low internal resistance. [ABSTRACT FROM AUTHOR]

MOFs (Metal–Organic Frameworks) are so-called coordination polymers with a porous crystalline structure. In this review, the main emphasis was placed on these compounds’ use in modifying titanium implants. The article describes what MOFs are, gives examples of ligands used in the synthesis of MOFs, and describes a subgroup of these materials, i.e., Zeolitic imidazolate frameworks. The article also lists the basic biomedical applications of these compounds. This review shows the significant impact of titanium surface modification with Metal–Organic Frameworks. These modifications make it possible to obtain layers with antibacterial properties, better corrosion resistance, increasing cell proliferation, faster bone growth in vivo, and much more. The presented work shows that the modification of titanium with MOFs is a very promising method of improving their properties. We hope that the prepared review will help research groups from around the world in the preparation of implants modified with Metal–Organic Frameworks with enhanced properties and utility applications.

Oxygen reduction reaction (ORR) has slow reaction rate that decrease the chemical conversion productivity in proton exchange membrane fuel cells (PEMFCs) which has to be improved. Noble metals such as Pt nanoparticles supported on carbon (Pt/C) was considered the most essential catalyst in ORR despite their limitations including being rare and expensive, CO poisoning etc. In the past few years, nitrogen doped carbons (N–C) or zeolitic imidazole framework (ZIFs) derived (M-N-C) including single or bimetallic metals take attention due to their outstanding properties such as high surface area, excellent electrical conductivity, cost effectiveness, thermal and chemical stability which were used either as catalyst or supports for noble metal nanoparticles to improve the sluggish ORR in PEMFC cathode. This review briefly outlines conventional crystal preparation and activation of porous carbons derived from ZIFs and their green synthesis methods, followed by modern synthesis methods of nanostructured MNP/MOF composites and recently their ORR activity evaluation in PEMFC. Particular attention was given to the porous carbon supports derived from two kind of frameworks such as ZIF-8 and ZIF-67 which are the most frequently reported ORR electrocatalysts and/or supports in the literature. [Display omitted] • Synthesis methods for zeolitic imidazolate frameworks (ZIFs) were summarized. • Utilization of ZIFs either catalyst or support were summarized. • ZIFs based porous carbon materials were evaluated in terms of ORR activity. [ABSTRACT FROM AUTHOR]