Hybrid Metal Organic Frameworks Research Articles

Metal-Organic Framework Hybrids Aid Metabolic Profiling for Colorectal Cancer.

Colorectal cancer (CRC) is the third most common fatal cancer worldwide, accounting for ≈10% of cancer-related mortality. Metabolic shift occurs from the very early stage during the development of CRC, which is of significant etiological and diagnostic importance toward precision medicine. Here, an advanced molecular tool to characterize the metabolic alterations in CRC, based on metal-organic framework (MOF) hybrids is reported. Consuming only 500 nL of plasma without any sample pretreatment, MOF hybrids yield direct metabolic fingerprints by laser desorption/ionization mass spectrometry in seconds. A diagnostic prediction model by a machine learning algorithm is constructed, to discriminate CRC patients from normal controls with an average area under the curve of 0.947 for the discovery cohort and 0.912 for the independent validation cohort. In addition, CRC-specific metabolic signature consisting of 34 potential biomarkers, based on the aforementioned diagnostic model is identified. The results advance the design of nanomaterial-based platforms for metabolic analysis and establish a new liquid biopsy tool for CRC screening compatible with the current clinical workflow in practice.

Rapid Exciton Migration and Amplified Funneling Effects of Multi-Porphyrin Arrays in a Re(I)/Porphyrinic MOF Hybrid for Photocatalytic CO2 Reduction.

A porphyrinic metal-organic framework (PMOF) known as PCN-222(Zn) was chemically doped with a molecular Re(I) catalyst-bearing carboxylate anchoring group to form a new type of metal-organic framework (MOF)-Re(I) hybrid photocatalyst. The porphyrinic MOF-sensitized hybrid (PMOF/Re) was prepared with an archetypical CO2 reduction catalyst, (L)ReI(CO)3Cl (Re(I); L = 4,4'-dicarboxylic-2,2'-bipyridine), in the presence of 3 vol % water produced CO with no leveling-off tendency for 59 h to give a turnover number of ≥1893 [1070 ± 80 μmol h-1 (g MOF)-1]. The high catalytic activity arises mainly from efficient exciton migration and funneling from photoexcited porphyrin linkers to the peripheral Re(I) catalytic sites, which is in accordance with the observed fast exciton (energy) migration (≈1 ps) in highly ordered porphyrin photoreceptors and the effective funneling into Re(I) catalytic centers in the Re(I)-doped PMOF sample. Enhanced catalytic performance is convincingly supported by serial photophysical measurements including decisive Stern-Volmer interpretation.

Charge separation in hybrid metal–organic framework films for enhanced catalytic CO2 conversion

A three-dimensional porous metal–organic framework-based hybrid film is prepared through a solid conversion process, demonstrating high photocatalytic performance for CO2 conversion under mild conditions.

Luminescence response mode and chemical sensing mechanism for lanthanide-functionalized metal–organic framework hybrids

This comprehensive review systematically summarizes the luminescence response mode and chemical sensing mechanism for lanthanide-functionalized MOF hybrids (abbreviated as LnFMOFH).

Photocatalytic cascade reactions and dye degradation over CdS-metal-organic framework hybrids.

Two bifunctional CdS–MOF composites have been designed and fabricated. The hybrids exhibited synergistic photocatalytic performance toward two cascade reactions under visible light integrating photooxidation activity of CdS and Lewis acids/bases of the MOF. The composite further promoted the photodegradation of dyes benefiting from effective electron transfer between the MOF and CdS.

Designing core–shell metal–organic framework hybrids: toward high-efficiency electrochemical potassium storage

Due to the unique core–shell structure which enables mutual advantage complement of the core and the shell, the electrochemical K+ storage property of core–shell MOF-derived nanoporous carbon is superior to that of single MOF-derived counterparts.

Enhanced electrical properties and restrained thermal transport in p- and n-type thermoelectric metal–organic framework hybrids

σ, S, and k match well with a parallel transport model in the hybrids.

Unlocking the potential of metal organic frameworks for synergized specific and areal capacitances via orientation regulation

Metal organic frameworks (MOFs) with numerous potential pseudocapacitive sites are quite appealing to supercapacitors with high specific and areal capacitances. However, MOFs suffer from a low conductivity nature, resulting in a mediocre electrochemical performance. Herein, we propose a template-growth strategy of MOF to enhance both specific and areal capacitances of MOF as the electrode material for supercapacitor. As the loading mass of MOF increases from 2 to 5 mg, the specific capacitance also increases from 937 to 2387 Fg−1 (431 to 1098 Cg−1) and areal capacitance 1.87 to 11.94 Fcm−2 (0.86 to 5.49 Ccm−1). Accordingly, a hybrid MOF//AC supercapacitor can deliver a maximum energy density of 67 Wh kg−1 and a maximum power density of 6000 W kg−1. These results point to a way to fabricate MOF electrode of supercapacitor with high specific and areal capacitance, which leads them to a more practical future.

Porous Metal-Organic-Framework (MOF) Based Hybrid Materials for Thermoelectric Applications

Thermoelectric materials based on porous hybrid and MOFs constitute a very recent development, with many new and undiscovered phenomena for the research field. These porous Hybrid materials and MOF (Metal-Organic-Framework) films represent modern designer materials that exhibit many requirements of a near ideal and tunable future thermoelectric (TE) material. It is anticipated that especially the inherent porosity can be used advantageously in the design and simulation predictions of future thermoelectric materials. In principle, porous Hybrid and MOFs materials can comply with most of the requirements of an ideal and tunable future thermoelectric (TE) material. In contrast to traditional semiconducting bulk thermoelectric materials, porous hybrid MOF templates can be used to overcome some of the constraints of physics in bulk thermoelectric materials. These porous hybrid systems are amenable for simulation and modeling to design novel optimized electron-crystal phonon-glass materials with potentially very high Figure of Merit (ZT) numbers. Porous MOF and Hybrid materials possess an ultra-low thermal conductivity, which can be further modulated by phonon engineering within their complex porous and hierarchical architecture to advance the thermoelectric figure of merit ZT. This class of novel materials offers new approaches to the design of complex and hierarchical porous structures, possessing ultra-low thermal conductivity, which are able to trap, and localize phonons, thus resulting in a new generation of thermoelectric materials with a high ZT number. This work is demonstrating recent results of MOF thermoelectric Materials and provides a future outlook to the search for the next generation thermoelectric porous Hybrid and MOF materials, which could be part of a green renewable energy revolution with novel materials of sustainable high ZT values.

Synthesis of Nitrogen‐Doped CNT‐Based MOF Hybrids for Adsorptive Desulfurization of the Gas Stream

AbstractIn this research, hybrids of N‐doped carbon nanotube (NCNT)‐based metal‐organic framework (MOF) (NCNT/UiO‐66 and NCNT/ZIF‐67) were synthesized using hydrothermal method. The performance of synthesized hybrids was evaluated in hydrogen sulfide removal under a dynamic system at 30–50 °C with 4500 ppm H2S concentration as inlet feed compared with neat UiO‐66 and ZIF‐67. NCNT/UiO‐66 and NCNT/ZIF‐67 were characterized using XRD, FTIR, FESEM, BET, and TGA. NCNT/ZIF‐67 and NCNT/UiO‐66 showed good adsorption capability for H2S with a capacity of 189.72 mg/g and 175.77 mg/g, respectively. The surface area of UiO‐66 and ZIF‐67 is (1351 and 1290 m2/g, respectively), and the addition of NCNT leads to the reduced surface area of nano adsorbent hybrids. Also, the performance of hybrids would not change after three cycles of the desulfurization process. These hybrids indicated the excellent potential for a desulfurization process.

Ultrasmall Mo2C in N-doped carbon material from bimetallic ZnMo-MOF for efficient hydrogen evolution

The exploration and development of cost-effective and highly stable electrocatalysts with the highest possible energy efficiency remain a constant pursuit in the catalyst design and synthesis for electrocatalytic hydrogen evolution reaction (HER). In this work, a convenient approach is proposed to synthesize a type of ultrafine Mo2C nanoparticles in average sizes of 3–4 nm embedded in hierarchically porous N-doped carbon material calcined from bimetallic ZnMo-MI (MI = 2-methylimidazole) is obtained at 1000 °C, denoted as ZnMo-MI-1000. First of all, the crystalline hybrid metal-organic framework of ZnMo-MI is fabricated from zeolitic imidazolate framework of Zn-MI precursors via solvothermal reaction, in which the conversion from Zn-MI to ZnMo-MI occurs gradually over time. After calcination, the as-obtained ZnMo-MI-1000 sample shows a satisfying HER performance with the small overpotential of 83.0 mV in 0.5 M H2SO4 and 100.1 mV in 1.0 M KOH to reach a current density of 10 mA cm−2, which is attributed to ultrasmall Mo2C, Mo and N-doped graphitic carbon matrix. The multiporous network of ZnMo-MI-1000 can provide continuous mass transportation with a minimal diffusion resistance that produce effective electrocatalytic kinetics in both acidic and alkaline media, which is utilized as a highly active and durable nonprecious metal electrocatalyst for HER.

Structural, thermal and electro-optical properties of guanidine based Metal-Organic Framework (MOF)

An hybrid metal-organic framework formulated as 3[2(CH6N3)+.Cl4 Mn(II)] has been synthesized by reflux condensation method of reacting guanidinium carbonate with manganese chloride. From synthesized material, good quality of single crystals have been harvested by solvent evaporation technique and characterized by single crystal XRD (SCXRD), DT-TGA analysis, UV–visible spectroscopy and Z-Scan. SCXRD investigation establishes that grown crystal crystallizes in the monoclinic crystal system with space group P 21/c. The crystal structure features strong metal-organic frameworks through Mn-Cl bonds, it limits its coordination for three adjacently connected octahedrons and making a closed metal-chlorine volume. Thermal properties have been examined by differential thermal (DT) and thermogravimetric analysis (TGA). Temperature and frequency-dependent dielectric properties have been investigated by LCR meter. The existence of third order nonlinear optical susceptibility and intensity tunable optical limiting responses have been confirmed by the Z-scan technique.

Fabrication and characterization of highly efficient three component CuBTC/graphene oxide/PSF membrane for gas separation application

Metal organic frameworks (MOFs) with marvelous properties have aroused enormous attention for different application especially gas adsorption and separation. In this regard, fabrication of MOF hybrids with carbon based materials is new strategy to upgrade MOF performance. In this study CuBTC (Copper benzene-1,3,5-tricarboxylic acid)/graphene oxide (GO) composite was synthesized and characterized by BET, SEM, TGA, XRD and FT-IR techniques. Then CuBTC and CuBTC/GO composite were incorporated into polysulfone (PSF) polymer to construct mixed matrix membranes (MMMs). The obtained membranes were characterized by SEM, TGA, XRD and tensile tests and their gas permeability was measured. The results were compared to those of CuBTC/PSF MMMs. It was revealed that CuBTC/GO composite as filler showed superior performance relative to CuBTC. For instance, 15 wt% loading of CuBTC/GO in PSF represented outstanding gas separation behavior while the same loading of CuBTC in PSF deteriorated performance of MMM. Well particle dispersion and favorable polymer-filler interaction were responsible for such observed difference. A high H2/CH4 and H2/N2 selectivity of 80.03 and 70.46 were recorded for CuBTC/GO in PSF (15 wt%) compared to 44.56 and 40.92 for CuBTC in PSF (15 wt%).

Tunable nonlinear optical responses based on host-guest MOF hybrid materials

The realization of tunable nonlinear optical (NLO) responses in a single nano-/micro-structure is extremely important. However, in lack of effective ways to integrate multiple performances, it still faces severe limitations during applications. Herein, we demonstrate a wavelength-dependent NLO micro-structure based on host-guest metal-organic framework (MOF) materials through encapsulating linear dye molecules into periodic one-dimensional (1D) channels. The confinement to non-centrosymmetric polar dye molecules enhances the second-/third-order NLO responses of the hybrid crystals, causing obvious two-photon luminescence (TPL), second harmonic generation (SHG) and third harmonic generation (THG) responses in the as-prepared composites. The highly ordered structures of MOFs impart spatial regulation on the linear dye molecules to realize orientation alignment, resulting in the polarized anisotropy emission. NIR-to-NIR (NIR, near-infrared region) two-photon pumped lasing is realized with the natural whispering gallery mode resonance cavities of MOFs under the excitation of a 1200-nm fs laser. Furthermore, tunable NLO properties such as TPL, SHG and THG are achieved through switching the incident excitation wavelength from 800 to 1500 nm. Such hybrid materials with tunable NLO responses may open a new avenue toward designing multifunctional NLO devices in the future.

Ion exchange based approach for rapid and selective Pb(II) removal using iron oxide decorated metal organic framework hybrid

Polyacrylic acid capped Fe3O4 – Cu-MOF (i-MOF) hybrid was prepared for rapid and selective lead removal, with 93% removal efficiency, exceptional selectivity, and adsorption capacity of 610 mg/g and 91% of i-MOF hybrid could be easily separated from the contaminated water using magnetic separation. The adsorption process followed a pseudo-second-order model and the adsorption efficiency decreased from 93% to 83% on raising the temperature from 25 °C to 40 °C. The change in equilibrium adsorption capacity with respect to equilibrium adsorbate concentration followed the Langmuir isotherm model. i-MOF had a high selectivity coefficient and removal efficiency for lead ions even when exposed simultaneously with naturally abundant cations (Na(I), Ca(II), Mg(II)). Release of Cu(II) ions from the i-MOF after Pb(II) removal suggested suggested ion-exchange to be the dominant removal mechanism. This new finding for Pb(II) removal with excellent adsorption performance using i-MOF through ion exchange based approach is a viable option for treating lead contaminated water.

Targeted synthesis of covalently linked Ni-MOFs nanosheets/graphene for oxygen evolution reaction by computational screening of anchoring primers

Hybridization of Metal-Organic frameworks (MOFs) with conductive materials has proven to be an efficient way to enhance their oxygen evolution reaction (OER) performance. Here we present a novel primer-induced in situ hybridization method to covalently link the nickel-based two-dimensional (2D) ultrathin MOFs nanosheets and graphene. By considering the energetically favorable anchoring process, thermodynamically prohibited self-polymerization side reaction and high delocalization of lowest unoccupied molecular orbitals (LUMO), the optimal phenylenebisboronic acid (PBA) primer were rapidly identified by screening thousands of primers via a high-throughput periodic density functional theory (DFT) workflow. Aided by the computational results, the PBA molecules were used to be covalently bonded to graphene successfully and then induce the in-situ growth of ultrathin Ni-MOFs nanosheets with terephthalic acid (TPA) as the ligand (denoted as Ni-HMOF@GE-PBA). The as-prepared Ni-HMOF@GE-PBA was demonstrated as a high-performance electrocatalyst for OER, delivering a much lower onset potential than that of simple blending of graphene and Ni-MOFs nanosheets by 150 mV. This design and construction strategy would pave an efficient pathway to rapid exploration and synthesis of new 2D–2D hybrid catalytic materials with excellent performance for OER. • The high-throughput calculation was applied to screen out the PBA as the primer from thousands of candidates. • A primer-induced in situ hybridization method was proposed and pave the pathway for constructing 2D-2D hybrid materials. • Excellent OER performance were achieved, delivering much better activity than commercial RuO 2 . • The electronic interaction study indicate the overlap of the orbitals is key to promote the electron transfer.

Cascade Reactions Catalyzed by Planar Metal-Organic Framework Hybrid Architecture for Combined Cancer Therapy.

Chemical transformation in cellular environment is critical for regulating biological processes and metabolic pathways. Harnessing biocatalytic cascades to produce chemicals of interest has become a research focus to benefit industrial and pharmaceutic areas. Nanoreactors, which can act as artificial cell-like devices to organize cascade reactions, have been recently proposed for potential therapeutic applications for life-threatening illnesses. Among various types of nanomaterials, there is a growing interest in 2D metal-organic frameworks (MOFs). By virtue of the ultralarge specific surface area, high porosity, and structural diversity, 2D MOF nanosheets hold great promise for a broad spectrum of biomedical use. Herein, a unique planar MOF-based hybrid architecture (GMOF-LA) is introduced by incorporating ultrasmall gold nanoparticles (Au NPs) as nanozyme and l-Arginine (l-Arg) as nitric oxide (NO) donor. The prepared Au NPs enable oxidation of glucose into hydrogen peroxide, which drives biocatalytic cascades to covert l-Arg into NO. Interestingly, the well-designed nanosheets not only possess excellent catalytical activity for NO generation, resulting in gas therapeutic effect, but also serve as a desired photosensitizer for photodynamic therapy. This study establishes a good example of exploring bioinspired nanoreactors for cooperative anticancer effect, which may pave the path for future "bench-to-bedside" design of nanomedicine.

Rational design of bimetallic metal–organic framework composites and their derived sulfides with superior electrochemical performance to remarkably boost oxygen evolution and supercapacitors

Developing highly efficient and stable multi-functional metal–organic framework electrochemical materials is of prime importance for renewable energy technologies and electrocatalytic applications. Herein, a novel series of bimetallic metal–organic framework (MOF) hybrid materials were successfully designedly fabricated through an in-situ growth and MOF-on-MOF strategies, namely as NiFeMOF/NF, NiCoMOF/NF, FeMOF/NiMOF/NF, and CoMOF/NiMOF/NF. Benefiting from the synergistic effect of bimetallic centers, conductive substrate and unique fabrication, they exhibit remarking electrochemical performance. Among them, FeMOF/NiMOF/NF composite with ultrathin nanosheets displays the best electrochecatalytic performance with ultralow overpotentials of 293 mV at 50 mA cm−2 and 359 mV at 100 mA cm−2 for oxygen evolution reaction (OER), and remarking electrochemical stability with high current density of 100 mA cm−2 after testing for 24 h, that 88% of initial current density can be remained. Based on these fabricated bimetallic MOF hybrid materials as precursors, the corresponding MOF-derived nano sulfides were obtained with massive exposure of active sites. As an excellent supercapacitor electrode, NiCoS/NF-1 converted from CoMOF/NiMOF/NF shows admirable specific capacitance of 2815.4 F g−1 at 1 mA cm−2 and a remarkable rate capability of 82%.

(Invited) Nanostructured Conjugated Materials in Metal-Organic Frameworks

As conjugated polymers play crucial roles in advanced nanoscale devices, future applications require a deeper understanding optoelectrical properties of conjugated polymers in low-dimensional assemblies. Confinement of polymer chains in nanoporous materials is a feasible method to control the polymer assemblies because this approach can prevent the entanglement and conformational disorder of polymer chains in the bulk state. The regulated and tailor-made pore characteristics of metal-organic frameworks (MOFs) allow the achievement of precise molecular assemblies in the nanopores, permitting fundamental studies on polymer properties that, until now, have remained elusive.1 Here, we report that the hybridization of MOFs and polythiophene (PTh) provides a great insight into inherent optoelectrical properties of PTh as well as functional nanomaterials for electronics and sensors.2 Controlled assembly of PTh donor and acceptor molecules is a key structure for photovoltaics and photocatalysis. We also demonstrated that unique interfaces between PTh and acceptor molecules, such as fullerene and titanium oxide, mediated by MOFs, enabled remarkable photoelectronic properties superior to conventional PTh systems.3 Other than conjugated polymers, a variety of conjugated materials, including graphene nanoribbons, could be prepared in MOFs, providing distinctly properties to those prepared in the bulk state because of the formation of specific assemblies.4 REFERENCES1. Chem. Soc. Rev. 2017, 46, 3108.2. (a) J. Am. Chem. Soc., 2015, 137, 5231. (b) Angew. Chem. Int. Ed., 2016, 55, 708. (c) Polym. Chem., 2017, 8, 5077. (d) Eur. Polym. J., 2018, 109, 162. (e) J. Am. Chem. Soc., 2019, 141, 19565.3. (a) Nat. Commun., 2018, 9, 1660. (b) J. Phys. Chem. C, 2018, 122, 24182.4. J. Am. Chem. Soc., 2020 , 142, 5509. Figure 1

Hydrothermal assembly, structural diversity, and photocatalytic characterization of two polyoxometalates-based hybrid CuII and CuI coordination polymers with 2,6-(1,2,4-triazole-4-yl)pyridine

In this work, under hydrothermal conditions, two novel polyoxometalates (POMs)-based CuII and CuI hybrid materials with 2,6-(1,2,4-triazole-4-yl)pyridine (L1), namely yellow block crystals [Cu2(L1)2(Mo4O13)] (1) and blue block crystals [Cu2(L1)3(H2O)2(Mo4O13)2] (2) have been designed and synthesized. These POM-based CuII and CuI hybrid materials 1–2 have been determined by single crystal X-ray diffraction analyses. In 1, these Mo8O26 4− anions and CuI centers are inter-linked by bidentate L1, which are arranged into the 1 D POMs-based CuI hybrid metal-organic framework. In 2, these L1 ligands bridge neighboring CuII centers and Mo8O26 4− anions, which ultimately form the unique 3 D POM-based CuII hybrid coordination framework of 2. Photocatalytic activities for decomposition of different organic dyes (Rhodamine B (RhB), methylene blue (MB) and methyl orange (MO)) have been investigated for 2, indicating that 2 are good candidates for the photocatalytic degradation of these organic dyes.