Porous Hybrid Materials Research Articles

Ionic Liquid‐Functionalized Porous Materials for Catalyzing CO2 Cycloaddition Reaction

AbstractIonic liquids (ILs) are incorporated into traditional porous materials to create ILs‐functionalized porous materials, which exhibit excellent absorption capacity and good catalytic activity for CO2. As a result, they are extensively utilized in the chemical conversion of CO2. This paper specifically focuses on the utilization of ILs‐functionalized organic porous materials, ILs‐functionalized inorganic porous materials, and ILs‐functionalized organic‐inorganic hybrid porous materials in the conversion of CO2. The synergistic effects of combining ILs with porous materials in CO2 conversion are thoroughly discussed. Furthermore, an in‐depth analysis is provided regarding the potential prospects and future applications of utilizing ILs‐functionalized porous materials within the broader realm of catalytic CO2 conversion technologies.

2D Microporous Polymers/Reduced Graphene Oxide with Built-In Lithiophilic Sites for Uniform Lithium Deposition in Lithium Metal Anode.

Lithium (Li) metal is an attractive anode material for use in high-energy lithium-sulfur and lithium-air batteries. However, its practical application is severely impeded by excessive dendrite growth, huge volume changes, and severe side reactions. Herein, a novel Li metal anode composed of lithiophilic two dimensional (2D) conjugated microporous polymer (Li-CMP) and reduced graphene oxide (rGO) sandwiches (Li-CMP@rGO) for Li metal batteries (LiMBs) is reported. In the Li-CMP@rGO anode, the conductive rGO facilitates the charge transfer while the functionalized-CMP provides Li nucleation sites within the micropores, thereby preventing dendrite growth. As a result, the Li-CMP@rGO anode can be cycled smoothly at 6mA cm-2 of current density with a platting capacity of 2 mAh cm-2 for 1000h. A Coulombic efficiency of 98.4% is achieved over 350 cycles with a low overpotential of 28mV. In a full cell with LiFePO4 cathode, the Li-CMP@rGO anode also exhibited good cycling stability compared to CMP@rGO and CMP/Super-P. As expected, the simulation results reveal that Li-CMP@rGO has a strong affinity for Li ions compared to CMP@rGO. The strategies adopted in this work can open new avenues for designing hybrid porous host materials for developing safe and stable Li metal anodes.

Metal-Organic Frameworks through the Lens of Artificial Intelligence: A Comprehensive Review.

Metal-organic frameworks (MOFs) are a class of hybrid porous materials that have gained prominence as a noteworthy material with varied applications. Currently, MOFs are in extensive use, particularly in the realms of energy and catalysis. The synthesis of these materials poses considerable challenges, and their computational analysis is notably intricate due to their complex structure and versatile applications in the field of material science. Density functional theory (DFT) has helped researchers in understanding reactions and mechanisms, but it is costly and time-consuming and requires bigger systems to perform these calculations. Machine learning (ML) techniques were adopted in order to overcome these problems by implementing ML in material data sets for synthesis, structure, and property predictions of MOFs. These predictions are fast, efficient, and accurate and do not require heavy computing. In this review, we discuss ML models used in MOF and their incorporation with artificial intelligence (AI) in structure and property predictions. The advantage of AI in this field would accelerate research, particularly in synthesizing novel MOFs with multiple properties and applications oriented with minimum information.

Mechanochemical "Cage-on-MOF" Strategy for Enhancing Gas Adsorption and Separation through Aperture Matching.

Post-modification of porous materials with molecular modulators has emerged as a well-established strategy for improving gas adsorption and separation. However, a notable challenge lies in maintaining porosity and the limited applicability of the current method. In this study, we employed the mechanochemical "Cage-on-MOF" strategy, utilizing porous coordination cages (PCCs) with intrinsic pores and apertures as surface modulators to improve the gas adsorption and separation properties of the parent MOFs. We demonstrated the fast and facile preparation of 28 distinct MOF@PCC composites by combining 7MOFs with 4 PCCs with varying aperture sizes and exposed functional groupsthrough a mechanochemical reactionin 5 mins. Only the combinations of PCCs and MOFs with closely matched aperture sizes exhibited enhanced gas adsorption and separation performance. Specifically, MOF-808@PCC-4 exhibited a significantly increased C2H2 uptake (+64%) and a longer CO2/C2H2 separation retention time (+40%). MIL-101@PCC-4 achieved a substantial C2H2 adsorption capacity of 6.11 mmol/g. This work not only highlights the broad applicability of the mechanochemical "Cage-on-MOF" strategy for thefunctionalization of a wide range of MOFs but also establishes potential design principles for the development of hybrid porous materials with enhanced gas adsorption and separation capabilities, along with promising applications in catalysis and intracellular delivery.

A Novel Ternary Catalyst PW4@MOF-808@SBA-15 for Deep Extraction Oxidation Desulfurization of Model Diesel.

In this work, a novel heterogeneous catalyst consisting of peroxophosphotungstate, microporous MOF-808, and mesoporous SBA-15 was synthesized, characterized, and used to remove sulfides from model fuel. The prepared material, PW4@MOF-808@SBA-15, exhibits excellent catalytic activity with a desulfurization efficiency of 99.8% in 60 min for multicomponent simulated fuel, and the desulfurization rate can reach more than 90% after ten consecutive cycles. The excellent catalytic activity and reusability are attributed to the hierarchically porous hybrid material MOF-808@SBA-15, which can effectively encapsulate PW4 and provide a site for the oxidation of sulfides.

In-situ growing Eu-MOF on TEMPO-oxidized cellulose nanofibers to form fluorescent films for Fe3+ detection

Metal-organic frameworks (MOFs) are porous hybrid materials made of metal and organic linkers. Combining MOFs with polymers enhances their performance and addresses the issue of low stability. In this study, a uniform nanoscale Eu(III)-based metal-organic framework (Eu-MOF) was synthesized and grown in situ on TEMPO(2,2,6,6-tetramethylpiperidinyl-1-oxide)-oxidized cellulose nanofibrils (TOCNF), resulting in the formation of Eu-MOF@TOCNF fluorescence films through vacuum filtration. These films exhibited favorable mechanical properties, high transmittance, and stable fluorescence characteristics within the pH range of 3–11. The film produced the characteristic emission peak of Eu3+, recognized the selective quenching of Fe3+ within 0–100μM, and displayed an inverse relationship between fluorescence intensity at 616 nm and Fe3+ concentration. This approach holds significant promise for Fe3+ detection in solutions and offers a novel strategy for developing highly efficient optical sensors based on fluorescence specificity.

High-performance solid-phase microextraction based on a nanocomposite sorbent of MOF/COF hybrid for ultra-trace analysis of trifluralin in food samples using the ion mobility spectrometer

Two well-known porous hybrid materials, a metal-organic framework (MOF) based on manganese and a melamine-rich covalent organic framework (COF) were combined, resulting in a highly effective nanocomposite sorbent of Mn-terephthalic acid (TA) /COF. After investigating the properties of the synthesized adsorbent, it was finally used as a new fiber for solid-phase microextraction. The method, named high-performance solid-phase microextraction (HPSPME), was utilized for the extraction and ultra-trace analysis of trifluralin in agricultural waters, fruit, and vegetable samples by using corona discharge ionization-ion mobility spectrometer (CD-IMS). To increase the extraction efficiency, experimental parameters including, temperature and time of extraction and desorption, solution pH, and stirring rate were optimized. Considering the optimized conditions, the enrichment factor of 2002, the limit of detection (LOD) 0.08 ng mL−1 (S/N=3), and linear dynamic range (LDR) 0.25–10.00 ng mL−1 with a coefficient of determination (R2=0.9987) were obtained. Relative standard deviations (RSDs, n = 3) of <9.7, <3.5, and <8.9 % were obtained, respectively, for reproducibility of the prepared fibers, intra- and inter-day. The relative recovery values for the real samples were 84–124 %. The proposed method’s accuracy for the sample impregnated with trifluralin was also evaluated by the EPA standard method.

Designing a novel 3D structured PVP-assisted Bi-TDC coordination polymers catalyst with tunable bandgap structure to decompose dyes

The exploration of an efficient porous hybrid materials is significant due to their unique properties and good development prospects in catalytic applications. Herein, the PVP-assisted 3D Bi-TDC (2,5-thiophene dicarboxylate acid) is designed by solvothermal reaction to capture solar and mechanical energy for the degradation of rhodamine B (RhB, 5 mg/L) and methylene blue (MB, 5 mg/L). The RhB and MB degradation of the PVP-assisted Bi-TDC reached 99.6 % and 90.2 % under the ultrasonic vibrations and photocatalysis, which displays a higher catalytic activity compared to the bare Bi-TDC. The obviously enhanced catalytic activity can be ascribed to the integrated of ultrasonic vibrations and photocatalysis, the efficient separation of electron-hole pairs and its uniform and regular structure. This present work provided a new strategy to develop a controllable structures and excellent catalytic material for the environmental and energy application.

Two-dimensional confined topotactic transformation to produce Co-Pi/Co3O4 hybrid porous nanosheets for promoted water oxidation

Exploring advanced electrocatalyst for the oxygen evolution reaction (OER) is of great importance in pursuing efficient and sustainable hydrogen production via electrolytic water splitting. Considering the structure–activity-stability relationship for designing advanced OER catalysts, two-dimensional (2D) porous catalyst with single crystallinity is deemed to be an ideal platform which could simultaneously endow enriched active sites, facile mass and charge transport ability as well as robust structural stability. Herein, we proposed a facile 2D confined topotactic phase transformation approach, which realizes the fabrication of highly porous single-crystalline Co3O4 nanosheets with in-situ surface modification of amorphous Co-Pi active species. Benefitted from the highly exposed undercoordinated cobalt sites, facilitated mass transport and facile 2D charge transfer pathway, the Co-Pi/Co3O4 hybrid porous nanosheets display enhanced OER activity with obvious pre-oxidation-induced activation. In addition, the operational stability was significantly improved owing to the strengthened structural stability which effectively buffers the internal strains and avoids the structural collapse during the electrochemical process. This work proposed a facile and mild method for the synthesis of amorphous/single-crystalline hybrid porous materials, and the achievement of synergistic modulation of active site density and charge transfer ability via targeted microstructural construction will shed light on catalyst design in the future.

Fibro-porous materials: 3D-printed hybrid porous materials for multifunctional applications

This work demonstrates the additive manufacturing of fibro-porous materials—hybrid materials with a fiber mesh integrated within the open cells of a base porous scaffold. The presented method allows seamless incorporation of fibers, with precise control of the fiber diameter and mesh density, into the scaffold without requiring any additional postprocessing steps. Here, using a gyroid pore architecture as the base scaffold, this study fabricates the fibro-porous materials using an extrusion-based additive technique and investigates their resultant sound absorption, pressure drop, mechanical stiffness, and energy absorption properties. Two-microphone normal incidence impedance tube measurements reveal significant improvements in the sound absorption performance compared to that of denser, fiberless porous material counterparts while maintaining a 33 % lighter weight. Additional tests, including pressure drop and static airflow resistivity measurements, indicate that fiber integration reduces the effective pore size and increases flow resistance, boosting sound absorption at lower frequencies. The mechanical properties are also markedly improved, with stiffness and yield stress increasing by 27 % and 37.85 %, respectively. The fibro-porous samples provide 30 % more energy absorption per unit volume due to their increased resistance to deformation. This research demonstrates that additively manufactured fibro-porous materials provide substantial multifunctional performance gains without significant weight increase. The adaptable manufacturing process is compatible with various extrudable materials and opens a new route to designing complex, customized engineering structures with application-specific functionalities.

Highly compressive aerogel-elastomer hybrid porous material with redistributed strain for high-sensitive soft pressure sensors

Owing to the good sensitivity and simple fabrication process, flexible piezoresistive pressure sensors based on aerogels shows great applications in soft robotics, bioelectronics and so on. However, the poor compressibility and stability of the aerogel is still challenging the development of aerogel based flexible piezoresistive pressure sensors, simultaneously, it is urgent to pave a way to enhance the sensitivity of these sensors. Here, for the first time, we propose a universal strategy to prepare aerogel skeleton-elastomer shell hybrid porous material with enhanced compressibility for high-sensitive and stable flexible pressure sensors. We found that the elastomer shell disperses the strain in the aerogel skeleton and enhances the compressibility of the aerogel, which improve the stability of the sensor (10000 cycles of compression). More importantly, there are elastomer micro-blocks formed in the hybrid material, these micro-blocks redistribute the strain in the material which contributes to the high sensitivity (10.25 kPa−1) of the sensors. Furthermore, the sensors are successful in monitoring both of the large joint bending and subtle skin vibration, as well as remote controlling toy car and artificial hand. This work provides an effective and universal strategy to enhance the sensitivity and stability of the aerogel based flexible pressure sensors and promotes their development towards practical applications.

Unexpected Molecular Sieving of Xylene Isomer Using Tethered Ligand in Polymer-Metal-Organic Frameworks (polyMOFs).

Promising advances in adsorption technology can lead to energy-efficient solutions in industrial sectors. This work presents precise molecular sieving of xylene isomers in the polymer-metal-oragnic framework (polyMOF), a hybrid porous material derived from the parent isoreticular MOF-1 (IRMOF-1). PolyMOFs are synthesized by polymeric ligands bridged by evenly spaced alkyl chains, showing reduced pore sizes and enhanced stabilities compared to its parent material due to tethered polymer bridge within the pores while maintaining the original rigid crystal lattice. However, the exact configuration of the ligands within the crystals remain unclear, posing hurdles to predicting the adsorption performances of the polyMOFs. This work reveals that the unique pore structure of polyIRMOF-1-7a can discriminate xylene isomers with sub-angstrom size differences, leading to highly selective adsorption of p-xylene over other isomers and alkylbenzenes in complex liquid mixtures (αpX/OM = 15 and αpX/OME = 9). The structural details of the polyIRMOF-1-7a are elucidated through computational studies, suggesting a plausible configuration of alkyl chains within the polyMOF crystal, which enable a record-high p-xylene selectivity and stability in liquid hydrocarbon. With this unprecedented molecular selectivity in MOFs, "polymer-MOF" hybridization is expected to meet rigorous requirements for high-standard molecular sieving through precisely tunable and highly stable pores.

Design of Hybrid Porous Materials for Obtaining and Storage of Gas Hydrates

Design of Hybrid Porous Materials for Obtaining and Storage of Gas Hydrates

Comparing The Catalytic Activity of Mg-BTC Metal Organic Framework and Post Synthetically Modified (TiO2 @ Mg-BTC) Metal Organic Framework for Cyanosilylation of Aldehydes

Metal organic frameworks (MOFs) are an emerging class of porous crystalline hybrid materials synthesised by the coordination of inorganic connectors and organic linkers, which has numerous potential applications in various fields. Here we report a comparative study on Mg-BTC MOF and TiO @Mg-BTC MOF as a heterogeneous catalyst. Mg-BTC MOF was synthesised by solvothermal method and subjected to comparative study with its post synthetically modified (PSM) counterpart to understand their catalytic behaviour for cyanosilylation of aldehydes. The synthesised Mg-BTC MOF and TiO @Mg-BTC MOF were characterised by powder XRD, BET surface area, SEM, FT-IR, TGA techniques. A detailed characterization study was performed to understand the correlation between catalytic activity and morphology of the assynthesized MOF and PSM-MOF. The catalytic activity of the hybrid materials were evaluated by GC-MS analysis. The results of the catalytic reactions revealed that post synthetically modified (TiO @Mg-BTC) MOF exhibited significantly higher catalytic activity compared to Mg-BTC MOF. The enhanced catalytic efficiency is due to the incorporation of TiO nanoparticles, which provides active sites for catalytic reactions under heterogeneous conditions. Even after repeated recycling and reuse, the catalytic ability of the catalyst retains. The impact of TiO on the framework shows variation in texture, surface area, thermal stability and catalytic behaviour on the MOF materials. Thus, our study emphasizes

Confinement-enhanced electrochemiluminescence by Ru(dcbpy)32+-functionalized γ-CD-MOF@COF-LZU1 porous hybrid material as micro-reactor for CYFRA 21-1 detection

The improvement of electrochemiluminescence (ECL) performance relies on the electron transfer efficiency between luminophore and coreactant. An ultrasensitive ECL micro-reactor with confinement-enhanced performance was prepared by using the covalent organic framework-LZU1-functionalized metal-organic framework (MOF@COF-LZU1) as a platform to assemble enormous N,N-dibutyl-2-hydroxyethylamine (DBAE) and tris(4,4′-dicarboxylic acid-2,2′-bipyridyl) ruthenium(II) [Ru(dcbpy)32+] into its pore channels. Compared to individual substances of γ-CD-MOF and COF-LZU1, the synergistic effects can conduce to the enhancement of the intensity, durability and sensitivity of the micro-reactor. Besides, COF-LZU1 can provide a mild environment to accommodate a certain amount of DBAE by concentrating them from the aqueous solution into its hydrophobic cavities and boost the oxidation efficiency of DBAE to generate more DBAE●+ and profited the survival of DBAE●, leading to an improved reaction efficiency with the Ru(dcbpy)32+ intermediate. Thanks to the confinement-enhanced strategy, engineered as high-functioning luminescent materials, Ru@γ-CD-MOF@COF-LZU1 micro-reactors decorated with Au NPs can facilitate electron transfer and capture primary antibodies (Ab1). Moreover, Au–Pd–Pt noble metal aerogels (NMAs) functionalized MoS2 NFs (Au–Pd–Pt NMAs@MoS2 NFs) were chosen as base material due to its large specific surface areas, high porosity, and excellent electrical conductivity. Based on above merits, the sensor demonstrated a sensitive response to CYFRA 21-1 detection in a linear concentration gradient from 10 fg/mL to 50 ng/mL with a detection limit of 0.0055 pg/mL (S/N = 3). The COF-LZU1 decorated ECL micro-reactors were constructed based on the signal amplification strategies to realize accurate CYFRA 21-1 detection.

Hollow Cobalt Carbide Cubes / Reduced Graphene Oxide Nanocomposite via Cyanide Coordination Polymer for Supercapacitor Applications

Coordination polymers, a broad class of porous hybrid materials resulting from the connection of metal ions with organic ligands, showcase enduring porosity, well-organised crystalline structures, and open metal active sites that augment their metal ions' redox activity. This investigation focuses on examining a nanocomposite composed of cobalt carbide/reduced graphene oxide (Co3C/rGO) prepared through the copolymer method, serving as an electrode material for supercapacitor devices. The nanocomposite's structure and hollow cubic morphology were confirmed through X-ray diffraction, Raman spectroscopy, and field emission scanning electron microscopy (FESEM) analysis. Electrochemical properties were thoroughly assessed using cyclic voltammetry, electrochemical impedance spectroscopy, and galvanostatic charge/discharge in 6M KOH with a voltage window of 0 V to 0.5 V. The Co3C/rGO electrode exhibited notable electrochemical performance, displaying a specific capacitance of 486.6 F g-1 at 1 mV s-1 and a low internal resistance of 0.58 Ω, surpassing existing literature due to its porous morphology. Additionally, to evaluate the nanocomposite's cycling stability, 5000 charge/discharge cycles were conducted, revealing a capacitive retention of 82% of its original capacitance after 5000 cycles. This underscores its excellent long-term durability as a high-performance material for supercapacitor applications.

Metal organic framework (MOF): Synthesis and fabrication for the application of electrochemical sensing

Metal-organic frameworks (MOF) are a class of porous hybrid materials of metal ions linked by organic bridging ligands. These materials consist of different families of crystalline frameworks with metal ions and metal-ion clusters linked by the coordination bonds with suitable organic ligands. These porous materials possess high surface area, variable pore sizes, various functions, and excellent thermal stability. As a result, these unique and tailored MOF materials found varied applications in electrochemical sensor development. The review critically examines the approach to synthesizing a wide range of MOF compounds. The utilization of MOF in fabricating a small-scale sensor device demonstrates the ability to detect various water contaminants in aquatic environments. Moreover, it showcased an in-depth advancement in sensor and device development utilizing MOFs materials. The efficient use of electrochemical sensors is discussed critically and presents these studies’ challenges and future perspectives.

Machine learned force-fields for an Ab-initio quality description of metal-organic frameworks

Metal-organic frameworks (MOFs) are an incredibly diverse group of highly porous hybrid materials, which are interesting for a wide range of possible applications. For a meaningful theoretical description of many of their properties accurate and computationally highly efficient methods are in high demand. These would avoid compromises regarding either the quality of modelling results or the level of complexity of the calculated properties. With the advent of machine learning approaches, it is now possible to generate such approaches with relatively little human effort. Here, we build on existing types of machine-learned force fields belonging to the moment-tensor and kernel-based potential families to develop a recipe for their efficient parametrization. This yields exceptionally accurate and computationally highly efficient force fields. The parametrization relies on reference configurations generated during molecular dynamics based, active learning runs. The performance of the potentials is benchmarked for a representative selection of commonly studied MOFs revealing a close to DFT accuracy in predicting forces and structural parameters for a set of validation structures. The same applies to elastic constants and phonon band structures. Additionally, for MOF-5 the thermal conductivity is obtained with full quantitative agreement to single-crystal experiments. All this is possible while maintaining a very high degree of computational efficiency. The exceptional accuracy of the parameterized force field potentials combined with their computational efficiency has the potential of lifting the computational modelling of MOFs to the next level.

Novel MOF/COF dual carrier anchoring Ru nanoparticles for improved hydrogen production by hydrolysis of NaBH4

Here, a facile bottom-up strategy has been employed to grow metal organic frameworks on covalent organic frameworks, forming a ZIF-67/JUC-505 dual-carrier material for the first time. Subsequently, ultrafine Ru nanoparticles (NPs) were loaded onto it through hydrogen reduction, resulting in the Ru-(ZIF-67/JUC-505) catalyst. Transmission Electron Microscope and Brunauer Emmett Teller analysis indicate that ZIF-67/JUC-505 possesses a porous structure with both micropores and mesopores, and the ruthenium anchored on it forms ultrafine Ru nanoparticles (< 2 nm). The specific surface area of Ru-(ZIF-67/JUC-505) obtained is 638.8 m²·g⁻¹ . The study on performance of NaBH4 hydrolysis illustrates that Ru-(ZIF-67/JUC-505) with 2.38 wt% Ru NPs has the highest catalytic activity. Specifically, the hydrogen generation rate (HG rate) of NaBH4 is 34790 mL∙min−1∙g−1 at 303 K, significantly higher than Ru/ZIF-67 (2511 mL∙min−1∙g−1) and Ru/JUC-505 (3794 mL∙min−1∙g−1) single-carrier catalysts. Meanwhile, the Ru-(ZIF-67/JUC-505) catalyst also shows excellent cycling stability, that is the Ru-(ZIF-67/JUC-505) still maintained 91.0% of its initial performance after 10 cycles. The mechanistic study indicates that the cycling stability is ascribed to the dual-carrier material ZIF-67/JUC-505. Exploring novel porous hybrid materials is of great significance, and it provides potential for material separation, catalysis and other related fields.

Fluorescence sensing and device fabrication with luminescent metal-organic frameworks.

Metal-organic frameworks (MOFs) are a novel class of hybrid porous multi-functional materials consisting of metal ions/clusters and organic ligands. MOFs have exclusive benefits due to their tunable structure and diverse properties. Luminescent MOFs (LMOFs) exhibit both porosity and light emission. They display abundant host and guest responses, making them conducive to sensing. Currently, LMOF sensing research is gaining more depth, with attention given to their device and practical applications. This work reviews recent advancements and device applications of LMOFs as chemical sensors toward ions, volatile organic compounds, biomolecules, and environmental toxins. Furthermore, the detection mechanism and the correlation between material properties and structure are elaborated. This analysis serves as a valuable reference for the preparation and efficient application of targeted LMOFs.