Versatile Metal-organic Frameworks Research Articles

A Two-Photon-Active Zr-Based Metal-Organic Framework-Based Orthogonal Nanoprobe for Recognition of Cellular Senescence.

A luminescent nanoprobe capable of orthogonal sensing of two independent events is highly significant for unbiased disease-related detection such as the detection of senescent cells. Moreover, it is invaluable that the nanoprobe possesses a two-photon excitable characteristic that is highly suitable for imaging living cells and tissues. Herein, we present a two-photon-excitable multiluminescent orthogonal-sensing nanoprobe (OS nanoprobe) capable of detecting both pH elevation and β-galactosidase (β-gal) overexpression in senescent cells. In the design, Zr-based dual-emissive metal-organic frameworks prepared from two mixed amino linkers, referred to as NH2-MU, were used as the component for the ratiometric sensing of pH; additionally, fluorogenic resorufin-β-d-galactopyranoside, linked to the NH2-MU framework, enables β-gal detection. In the OS nanoprobe, the signals for pH and β-gal sensing remain independent while maintaining high colocalization. The two-photon excitable organic linkers of NH2-MU impart the OS nanoprobe with a bioimaging capability, allowing for the differentiation of senescent human foreskin fibroblast (HFF) cells from younger HFF cells or LacZ positive cells with the 800 nm laser excitation. This study marks the first instance of achieving the multiplexed orthogonal fluorescent sensing of cellular senescence using a two-photon excitation strategy, suggesting the potential of using versatile metal-organic framework (MOFs)-based fluorophores to realize the orthogonal multiplexing of disease-related biomarkers through multiphoton excitation.

Building Co16‐N3‐Based UiO‐MOF to Expand Design Parameters for MOF Photosensitization

AbstractThe construction of secondary building units (SBUs) in versatile metal–organic frameworks (MOFs) represents a promising method for developing multi‐functional materials, especially for improving their sensitizing ability. Herein, we developed a dual small molecules auxiliary strategy to construct a high‐nuclear transition‐metal‐based UiO‐architecture Co16‐MOF‐BDC with visible‐light‐absorbing capacity. Remarkably, the N3− molecule in hexadecameric cobalt azide SBU offers novel modification sites to precise bonding of strong visible‐light‐absorbing chromophores via click reaction. The resulting Bodipy@Co16‐MOF‐BDC exhibits extremely high performance for oxidative coupling benzylamine (~100 % yield) via both energy and electron transfer processes, which is much superior to that of Co16‐MOF‐BDC (31.5 %) and Carboxyl @Co16‐MOF‐BDC (37.5 %). Systematic investigations reveal that the advantages of Bodipy@Co16‐MOF‐BDC in dual light‐absorbing channels, robust bonding between Bodipy/Co16 clusters and efficient electron‐hole separation can greatly boost photosynthesis. This work provides an ideal molecular platform for synergy between photosensitizing MOFs and chromophores by constructing high‐nuclear transition‐metal‐based SBUs with surface‐modifiable small molecules.

Building Co16-N3-Based UiO-MOF to Expand Design Parameters for MOF Photosensitization.

The construction of secondary building units (SBUs) in versatile metal-organic frameworks (MOFs) represents a promising method for developing multi-functional materials, especially for improving their sensitizing ability. Herein, we developed a dual small molecules auxiliary strategy to construct a high-nuclear transition-metal-based UiO-architecture Co16-MOF-BDC with visible-light-absorbing capacity. Remarkably, the N3 - molecule in hexadecameric cobalt azide SBU offers novel modification sites to precise bonding of strong visible-light-absorbing chromophores via click reaction. The resulting Bodipy@Co16-MOF-BDC exhibits extremely high performance for oxidative coupling benzylamine (~100 % yield) via both energy and electron transfer processes, which is much superior to that of Co16-MOF-BDC (31.5 %) and Carboxyl @Co16-MOF-BDC (37.5 %). Systematic investigations reveal that the advantages of Bodipy@Co16-MOF-BDC in dual light-absorbing channels, robust bonding between Bodipy/Co16 clusters and efficient electron-hole separation can greatly boost photosynthesis. This work provides an ideal molecular platform for synergy between photosensitizing MOFs and chromophores by constructing high-nuclear transition-metal-based SBUs with surface-modifiable small molecules.

Electronic metal-support interactions for defect-induced Ru/Co-Sm2O3 mesosphere to achieve efficient NaBH4 hydrolysis activity

Crafting resilient catalysts that promote H2 production through the hydrolysis of hydrogen storage materials like sodium borohydride stands paramount for the impending hydrogen economy. In this study, we propose a versatile metal–organic framework (MOF)-assisted approach to systematically explore the impact of electron-metal support interaction (EMSI) of Ru-modified Co-Sm2O3 (Ru/Co-Sm2O3) on H2 evolution from NaBH4 hydrolysis. Strategic annealing at 800 °C induces cobalt vacancies on the Ru/Co-Sm2O3 surface, optimizing the exposure of active sites and amplifying mass-charge transfer efficiency. Consequently, the defect-enriched Ru/Co-Sm2O3 showcases an impressive hydrogen generation rate (HGR = 0.430 mol min−1 gcatalyst−1) and outstanding cycling resilience, eclipsing the performance of most contemporary catalysts. Experimental findings reveal that Sm can not only adjust the Ru lattice spacing to accommodate more BH4−, but also modulate the Co vacancy concentration, thus bolstering the charge transport and ameliorating the catalyst's electrical conductivity. DFT calculations confirm that the Michaelis-Menten/Eley-Rideal mechanism is more appropriate to explain the hydrolysis of NaBH4.

Atomic-resolution structure analysis inside an adaptable porous framework

We introduce a versatile metal-organic framework (MOF) for encapsulation and immobilization of various guests using highly ordered internal water network. The unique water-mediated entrapment mechanism is applied for structural elucidation of 14 bioactive compounds, including 3 natural product intermediates whose 3D structures are clarified. The single-crystal X-ray diffraction analysis reveals that incorporated guests are surrounded by hydrogen-bonded water networks inside the pores, which uniquely adapt to each molecule, providing clearly defined crystallographic sites. The calculations of host-solvent-guest structures show that the guests are primarily interacting with the MOF through weak dispersion forces. In contrast, the coordination and hydrogen bonds contribute less to the total stabilization energy, however, they provide highly directional point interactions, which help align the guests inside the pore.

Microwave-assisted production of metal-organic frameworks for water purification: A mini-review

Metal-organic frameworks (MOFs) have been demonstrated to be the “star” functional materials for pollutants elimination from wastewater. The microwave (MW)-assisted method can accomplish higher MOFs yield within shorter time than conventional approaches, which can produce desired MOFs with the larger BET surface area and higher catalytic performance. Herin, the various MW-assisted methods, and the corresponding influences of various factors (including synthesis time, solvent, temperature) on the yields and physicochemical properties of the as-prepared MOFs were summarized and discussed in detail. Moreover, the adsorption, catalytic oxidation and catalytic reduction performances of as-prepared MOFs were highlighted. Finally, the future challenges and opportunities of MOFs prepared via MW-assisted method for water purification are proposed, which might provide useful information for designing and producing the versatile MOFs via MW-assisted methods.

A versatile MOF liquids-based Janus fibrous membrane towards complex oil/water separation and heavy metal ions removal

As an emerging material, porous liquids (PLs) have attracted wide attention and are applied in oily wastewater for the effective elimination of heavy metal ions due to their permanent pore structure, mobility, and superhydrophilicity. However, it remains a challenge to further enhance the separation performance of PLs. Here, a novel metal–organic framework (MOF) porous liquid was synthesized and mixed with a polyacrylonitrile (PAN) solution to produce an asymmetrical Janus fibrous membrane by electrostatic spinning technique. Benefiting from the synergistic effect of the electric field and self-migrating properties of MOF PLs, the Janus membranes exhibited ultrahigh flux of 25310.26 L m-2h−1 bar−1, outstanding separation efficiency (reaching up to 99.99 %) in various oil–water emulsions and high antimicrobial activity (>99.9 %). More impressively, the obtained Janus membranes maintained long-term stability, with separation efficiencies consistently as high as 99.5 %. Meanwhile, the porous structure of MOF PLs with abundant active sites and affinity of polyethylene glycol (PEG) flexible chain for metal ions facilitates the adsorption of metal ions with a maximum equilibrium adsorption capacity of 205 mg/g, which is superior to other literature reported. These results demonstrated that the versatile MOF PLs-based Janus fibrous membranes had a promising application prospect in addressing the challenges associated with such wastewater treatment.

In-situ synthesis of dual functionalized MOF by engineering modulator induced defect for efficient remediation of aqueous mercury through adsorption

UiO-66 is an extremely versatile metal organic framework (MOF) due to its remarkable water stability and high specific surface area. The incorporation of modified chemical and structural defects (missing linker and missing cluster defects) into the crystalline UiO-66 by the simultaneous use of an amino modified ligand and a thiol containing monocarboxylic acid modulator (thioglycolic acid, TGA) during synthesis resulted in developing a novel dual-functional MOF, designated as NH2-UiO-66-SH_C. This material was characterized using FTIR, XRD, FESEM, EDX, XPS, BET and Zetasizer to explore the morphological integrity and chemical composition. NH2-UiO-66-SH_C crystals demonstrated irregular nano-sized morphology (< 100 nm) and microporous nature with specific surface area of 519.6 m2/g. The material was subsequently tested to adsorb the highly toxic aqueous mercury (Hg) which is responsible for severe damages to human health. The maximum adsorptive capacity for aqueous inorganic mercury was 885 mg/g at 303 K. The optimum adsorbent dose and solution pH were 0.3 g/L and 5, respectively. The adsorption was endothermic and followed pseudo-second order kinetics. The developed nano-adsorbent illustrated enhanced sorption capacities which were far higher compared to its parent MOFs (UiO-66 as well as NH2-UiO-66) and other reported modified forms of UiO-MOFs. A regeneration method that was effective over 5 cycles (Hg removal efficiency > 90%) was also reported. Overall, this study reports the development of a newly modified nano-crystalline MOF, by manipulation of the synthetic chemistry (with defect modulation), which is a promising adsorbent for Hg (II) in aqueous phase.

Phytic acid-derivative Co2B-CoPOx coralloidal structure with delicate boron vacancy for enhanced hydrogen generation from sodium borohydride

Application of transition metal boride (TMB) catalysts towards hydrolysis of NaBH4 holds great significance to help relieve the energy crisis. Herein, we present a facile and versatile metal-organic framework (MOF) assisted strategy to prepare Co2B-CoPOx with massive boron vacancies by introducing phytic acid (PA) cross-linked Co complexes that are acquired from reaction of PA and ZIF-67 into cobalt boride. The PA etching effectively breaks down the structure of ZIF-67 to create more vacancies, favoring the maximal exposure of active sites and elevation of catalytic activity. Experimental results demonstrate a drastic electronic interaction between Co and the dopant phosphorous (P), thereby the robustly electronegative P induces electron redistribution around the metal species, which facilitates the dissociation of B-H bond and the adsorption of H2O molecules. The vacancy-rich Co2B-CoPOx catalyst exhibits scalable performance, characterized by a high hydrogen generation rate (HGR) of 7716.7 mL min−1 g−1 and a low activation energy (Ea) of 44.9 kJ/mol, rivaling state-of-the-art catalysts. This work provides valuable insights for the development of advanced catalysts through P doping and boron vacancy engineering and the design of efficient and sustainable energy conversion systems.

Prediction of Carbon Dioxide and Methane Adsorption on UiO-66 Metal–Organic Framework via Molecular Simulation

The adsorption equilibrium of methane (CH4) and carbon dioxide (CO2) on the metal–organic framework (MOF) UiO-66 is studied via molecular simulation. UiO-66 is a versatile MOF with vast potential for various adsorption processes, such as biogas upgrading, CO2 capture, and natural gas storage. The molecular simulations employ the grand canonical Monte Carlo (GCMC) method, covering a temperature range of 298–343 K and pressures up to 70 bar for CH4 and 30 bar for CO2. The accuracy of different forcefields in describing the adsorption equilibria is evaluated. Two modelling approaches are explored: (i) lumping each hydrogen atom in the MOF framework to the heavy atom it is bonded to (united atom approximation) and (ii) considering explicit hydrogen atoms. Additionally, the influence of electrical charges on CO2 adsorption is also evaluated. The findings indicate that the most effective forcefield to describe the adsorption equilibrium is a united atom forcefield based on the TraPPE parametrization. This approach also yields an accurate calculation of the isosteric heat of adsorption. In the case of CO2, it is observed that the use of electrical charges enhances the prediction of the heat of adsorption, especially in the low-coverage region.

Microporous Organic Network: Superhydrophobic Coating to Protect Metal-Organic Frameworks from Hydrolytic Degradation.

Despite the rapid development of versatile metal-organic frameworks (MOFs), the synthesis of water-stable MOFs remains challenging, which significantly limits their practical applications. Herein, a novel engineering strategy was developed to prepare superhydrophobic MOFs by an in situ fluorinated microporous organic network (FMON) coating. Through controllable modification, the resulting MOF@FMON retained the porosity and crystallinity of the pristine MOFs. Owing to the superhydrophobicity of the FMON and the feasibility of MOF synthesis, the FMON coating could be in situ integrated with various water-sensitive MOFs to provide superhydrophobicity. The coating thickness and hydrophobicity of the MOF@FMON composites were easily regulated by changing the FMON monomer concentration. The MOF@FMON composites exhibited excellent oil/water separation and catalytic activities and enhanced durability in aqueous solutions. This study provides a general approach for the synthesis of superhydrophobic MOFs, expanding the application scope of MOFs.

Application of photo-responsive metal-organic framework in cancer therapy and bioimaging

Metal-organic frameworks (MOFs) are a class of hybrid porous crystalline materials that are assembled with metal ions/clusters and organic linkers. The fungibility of organic ligands and metal centers endow MOFs that are easy to design and synthesize. Based on their unique structure, multifarious MOFs with diverse functionalities have recently been widely applied in various research areas. Particularly striking is the application of photo-responsive MOFs in biological sensing and imaging. Notably, the photoelectronic properties make photo-responsive MOFs an ideal platform for cancer phototherapy. Moreover, ultrahigh porosities and tunable pore sizes allow MOFs to load anticancer drugs, further enhancing the antitumor efficiency. In this review, the categories and developing strategies of MOFs are briefly introduced. The application fields of MOFs in bioimaging, such as up-conversion fluorescence imaging, single/two-photon fluorescence bioimaging, magnetic resonance imaging, etc., are summarized. The working mechanism of MOFs in photo-responsive, photothermal therapy (PTT), and photodynamic therapy (PDT) are expounded. Examples of using MOFs for cancer treatment, including PTT, PDT, chemotherapy, and radiotherapy, are also demonstrated. Lastly, current limitations, challenges, and future perspectives for bioimaging and cancer treatment of MOFs are discussed. We believe that the versatile MOF will bring the dawn to the next generation of cancer treatment.

Microwave pyrolysis-engineered MOFs derivatives for efficient preferential CO oxidation in H2-rich stream

Microwave pyrolysis inherited the molecular-level engineering design of the CuCe-MOF: The tandem microwave pyrolysis firstly carbonized them to CuCe/C with topological structure, and improved the microwave absorption of MOFs in nitrogen atmosphere. Subsequently, CuCeO x catalyst was synthesized by its self-heating source of microwave in air, which endowed with molecular-level dispersed active sites to enhance preferential CO oxidation in H 2 -rich stream. • MOFs derivatives are achieved via tandem microwave pyrolysis. • Microwave pyrolysis inhibits the agglomeration of metal nanoclusters. • The tandem strategy solves the problem of poor microwave adsorption of MOFs. • Ligand carbonization provides dispersed heating sources by enhancing microwave absorption. • Microwave pyrolysis-engineered CuCeO x exhibits an outstanding performance of preferential CO oxidation. The versatile metal–organic framework (MOF) derivatives are achieved via microwave pyrolysis. The dipole vibration thermogenesis of molecules by microwave pyrolysis overcomes the issues of high energy consumption, slow heating rate, unregulated at the molecular-level, metal nanoclusters particles migration and coalescence caused by traditional thermal pyrolysis. For solving the poor microwave absorption of MOFs, a tandem microwave pyrolysis strategy is employed herein. Ligand carbonization enhances the conduction loss of microwaves and becomes a highly dispersed microwave heating source, which effectively inhibits the agglomeration. The CuCeO x catalysts obtained through this strategy retain the merits of bimetallic CuCe-MOFs with highly dispersed active species, and exhibit outstanding catalytic activities with the 100% conversion of CO being achieved at 75 °C for the preferential CO oxidation in H 2 -rich stream. These results demonstrate that the microwave pyrolysis-engineered MOFs uniformity has established catalyst with highly dispersed active species.

Dirac Point Modulated Self-Powered Ultrasensitive Photoresponse and Color-Tunable Electroluminescence from Flexible Graphene/Metal–Organic Frameworks/Graphene Vertical Phototransistor

Integrated wearable optoelectronic devices synchronously exhibit contradictory phenomena of exciton generation and recombination with their control by an external electric field, and the mechanical strain associated with this has widespread applications. However, a demonstration of such single-miniaturized multifunctional wearable optoelectronics remains a daunting challenge. A versatile metal–organic framework (MOF) possesses tailorable outstanding optical properties through an inherent multiple charge-transfer mechanism between metal and ligand. Yet, its commercialization remains unsuccessful because of large porosity, poor conductivity, and deficient crystallinity. Graphene is honorable for its outstanding optoelectronic and mechanical behaviors. Combining excellent features of a versatile MOF with monolayer graphene, unprecedently, we report a self-powered ultrasensitive (external quantum efficiency ∼3 × 1010%) and ultrafast (response time ≈ 220 μs) wearable vertical phototransistor by utilizing a graphene/MOF/graphene/poly(vinylidene fluoride-co-trifluoroethylene) heterojunction on a flexible polydimethylsiloxane substrate through the formation of asymmetric Schottky junctions at MOF/graphene interfaces by a judicious incorporation of a piezo-sensitive poly(vinylidene fluoride) layer. Importantly, by the Dirac point modulation of graphene through a mechanical strain, we achieve optical strain sensors that can modify the amplitude and polarity of the photocurrent. Additionally, controlling the Dirac point of graphene and charge-transfer mechanisms of the MOF by a suitable electrical bias and strain, we demonstrate color-tunable broadband light emission from a flexible vertical phototransistor. Our unique discovery will enrich wearable integrated optoelectronics.

Versatile metal-organic frameworks as a catalyst and an indicator of nitric oxide.

The imaging of nitric oxide (NO) and its donors is crucial to explore NO-related physiological and pathological processes. In this work, we demonstrate the use of Cu-based metal-organic frameworks (Cu-MOFs) as nanoprobes for NO detection and as a catalyst for the generation of NO from the biologically occurring substrate, S-nitrosothiols (RSNOs). The paramagnetic Cu2+ in the MOFs could quench the luminescence of triphenylamine; Cu-MOFs only exhibited weak emission at 450 nm. Upon the addition of NO, the paramagnetic Cu2+ was reduced to diamagnetic Cu+, and thus the luminescence was recovered directly. Cu-MOFs exhibited high selectivity for other species in the reaction system, including NO2-, H2O2, AA, NO3- and 1O2. More significantly, the Cu+ can react with s-nitrosoglutathione (GSNO), s-nitrosocysteine (CysNO), and s-nitrosocysteamine (CysamNO) to generate NO and then oxidize to Cu2+-MOFs with quenched luminescence, respectively, and thus the catalysis is inhibited, noted as a self-controlled process. The Cu-MOFs catalyst was confirmed by powder X-ray diffraction to remain structurally intact in aqueous environments. The Cu-MOFs have been successfully employed in the biological imaging of NO in living cells. The bifunctional MOFs could offer a novel platform for the real-time monitoring of NO species, provide potential for exploiting NO in cancer therapy and improve the methodologies to elucidate the NO-related biological processes.

The uptake of metal-organic frameworks: a journey into the cell.

The application of metal–organic frameworks (MOFs) in drug delivery has advanced rapidly over the past decade, showing huge progress in the development of novel systems. Although a large number of versatile MOFs that can carry and release multiple compounds have been designed and tested, one of the main limitations to their translation to the clinic is the limited biological understanding of their interaction with cells and the way they penetrate them. This is a crucial aspect of drug delivery, as MOFs need to be able not only to enter into cells but also to release their cargo in the correct intracellular location. While small molecules can enter cells by passive diffusion, nanoparticles (NPs) usually require an energy-dependent process known as endocytosis. Importantly, the fate of NPs after being taken up by cells is dependent on the endocytic pathways they enter through. However, no general guidelines for MOF particle internalization have been established due to the inherent complexity of endocytosis as a mechanism, with several factors affecting cellular uptake, namely NP size and surface chemistry. In this review, we cover recent advances regarding the understanding of the mechanisms of uptake of nano-sized MOFs (nanoMOFs)s, their journey inside the cell, and the importance of biological context in their final fate. We examine critically the impact of MOF physicochemical properties on intracellular trafficking and successful cargo delivery. Finally, we highlight key unanswered questions on the topic and discuss the future of the field and the next steps for nanoMOFs as drug delivery systems.

Light-Activated Fuel-Free Janus Metal Organic Framework Colloidal Motors for the Removal of Heavy Metal Ions.

Light-powered fuel-free colloidal motors possess significant potential for practical applications ranging from nanomedicine to environmental remediation. However, current light-powered colloidal motors often require the incorporation of expensive metals or high concentrations of toxic chemical fuels, which is a severe limitation for their practical applications. Integrating highly ordered and porous materials with a large surface area into colloidal motors is a promising strategy for upsurging their self-propelled speed and adsorption, which will benefit many applications. Here, highly efficient, fuel-free, and light-activated metal organic framework (MOF)-3-trimethoxysilyl propyl methacrylate Janus colloidal motors with a hierarchical morphology are reported. These colloidal motors can be driven by UV or visible light, with a self-propelled speed tuned by the light intensity. The speed can be further enhanced by morphology optimization or by the addition of H2O2 as a fuel. The colloidal motors display a superior efficiency in removing heavy metal ions of Hg, which is up to ∼90% within 40 min from the contaminated water, attributed to their high surface area, hierarchical morphology, large number of active sites, and high mobility. This work not only offers a facile approach to incorporate a versatile MOF family into the design of fuel-free and light-powered Janus colloidal motors, but also demonstrates their potential for real-life applications such as environmental remediation.

Photothermal therapy with regulated Nrf2/NF-κB signaling pathway for treating bacteria-induced periodontitis

Periodontitis is an inflammatory disease initiated by bacterial infection, developed by excessive immune response, and aggravated by high level of reactive oxygen species (ROS). Hence, herein, a versatile metal-organic framework (MOF)-based nanoplatform is prepared using mesoporous Prussian blue (MPB) nanoparticles to load BA, denoted as MPB-BA. The established MPB-BA nanoplatform serves as a shelter and reservoir for vulnerable immunomodulatory drug BA, which possesses antioxidant, anti-inflammatory and anti-bacterial effects. Thus, MPB-BA can exert its antioxidant, anti-inflammatory functions through scavenging intracellular ROS to switch macrophages from M1 to M2 phenotype so as to relieve inflammation. The underlying molecular mechanism lies in the upregulation of phosphorylated nuclear factor erythroid 2-related factor 2 (Nrf2) to scavenge ROS and subsequently inhibit the nuclear factor kappa-B (NF-κB) signal pathway. Moreover, MPB-BA also exhibited efficient photothermal antibacterial activity against periodontal pathogens under near-infrared (NIR) light irradiation. In vivo RNA sequencing results revealed the high involvement of both antioxidant and anti-inflammatory pathways after MPB-BA application. Meanwhile, micro-CT and immunohistochemical staining of p-Nrf2 and p-P65 further confirmed the superior therapeutic effects of MPB-BA than minocycline hydrochloride. This work may provide an insight into the treatment of periodontitis by regulating Nrf2/NF-κB signaling pathway through photothermal bioplatform-assisted immunotherapy.

Polydopamine-Modified Metal-Organic Frameworks, NH2-Fe-MIL-101, as pH-Sensitive Nanocarriers for Controlled Pesticide Release.

Recently, metal–organic frameworks (MOFs) have become a dazzling star among porous materials used in many fields. Considering their intriguing features, MOFs have great prospects for application in the field of sustainable agriculture, especially as versatile pesticide-delivery vehicles. However, the study of MOF-based platforms for controlled pesticide release has just begun. Controlled pesticide release responsive to environmental stimuli is highly desirable for decreased agrochemical input, improved control efficacy and diminished adverse effects. In this work, simple, octahedral, iron-based MOFs (NH2-Fe-MIL-101) were synthesized through a microwave-assisted solvothermal method using Fe3+ as the node and 2-aminoterephthalic acid as the organic ligand. Diniconazole (Dini), as a model fungicide, was loaded into NH2-Fe-MIL-101 to afford Dini@NH2-Fe-MIL-101 with a satisfactory loading content of 28.1%. The subsequent polydopamine (PDA) modification could endow Dini with pH-sensitive release patterns. The release of Dini from PDA@Dini@NH2-Fe-MIL-101 was much faster in an acidic medium compared to that in neutral and basic media. Moreover, Dini@NH2-Fe-MIL-101 and PDA@Dini@NH2-Fe-MIL-101 displayed good bioactivities against the pathogenic fungus causing wheat head scab (Fusarium graminearum). This research sought to reveal the feasibility of versatile MOFs as a pesticide-delivery platform in sustainable crop protection.

ZIF‐8 MOF Encapsulated Co‐porphyrin, an Efficient Electrocatalyst for Water Oxidation in a Wide pH Range: Works Better at Neutral pH

AbstractWater oxidation (WO) is the most important and thermodynamically challenging process associated with water splitting. Several metal porphyrins are reported to perform catalytic WO through the central metal but [5,10,15,20‐tetrakis(4‐methoxyphenyl)porphyrinato]cobalt(II) (abbreviated as CoTMPP), which is well‐known for its ability to perform oxygen reduction reaction (ORR), lacks the capacity to perform WO. Here we have successfully activated CoTMPP towards electrochemical WO by means of its in situ encapsulation inside the cavity of a versatile metal organic framework (MOF), known as zeolitic imidazolate framework‐8 (ZIF‐8). The composite, thus prepared i. e., CoTMPP@ZIF‐8 (abbreviated as CTMZ‐8), behaves as a heterogeneous, robust, and efficient electrocatalyst for oxygen evolution reaction (OER) at a wide pH range (from acidic to neutral). Required overpotential (η) of 387.4 mV (neutral pH) and 562.7 mV (pH 2) and high turnover frequency (TOF) of 2.7 s−1 (at neutral pH) make this composite (CTMZ‐8) an efficient electrocatalyst for WO. To the best of our knowledge, this is the first report of electrocatalytic WO by CoTMPP.