Functional Metal-organic Frameworks Research Articles

Challenges and recent advances in MOF-based gas separation membranes.

Membrane-based gas separation, characterized by a small footprint, low energy consumption and no pollution, has gained widespread attention as an environmentally friendly alternative to traditional gas separation. Metal-organic-frameworks (MOFs) are considered to be one of the most promising membrane-based gas separation materials because of their large specific surface area and high porosity. One of the hottest studies at the moment is how to utilize the characteristics of MOFs to prepare higher performance gas separation membranes. This paper provides a review of gas separation membranes used in recent years. Firstly, the synthesis methods of MOFs and MOF membranes are briefly introduced. Then, methods to improve the membrane properties of MOFs are described in detail, and include applications of lamellar MOFs, ionic liquid (IL) spin coating, functionalization of MOFs, defect engineering and mixed fillers. In addition, the challenges of MOF-based gas separation membranes are presented, including pore size, environmental disturbances, plasticization, interfacial compatibility, and so on. Finally, based on the current development status of the MOF membranes, the development prospects of MOF gas separation membranes are discussed. It is hoped to provide reliable and complete ideas for researchers to prepare high-performance gas separation membranes in the future.

A novel porphyrin MOF catalyst for efficient conversion of CO2 with propargyl amines.

The capture and conversion of carbon dioxide (CO2) into valuable chemical products under mild conditions is an important and challenging approach for contemporary industry. Carboxylic acid ligands are widely used in the development of functionalized metal organic framework materials due to their excellent stability. Herein, a novel mixed-metal organic framework Cu-TCPP(Fe) was assembled from iron-(Fe)-porphyrin ligands, which can efficiently catalyze the reaction of propargylic amines and CO2 to synthesize 2-oxazolidinones.

Synergistic antibacterial effect of quaternary ammonium salt functionalized metal–organic framework

Pseudomonas aeruginosa (P. aeruginosa) can be an important causative factor for severe infections in humans, especially in patients with respiratory infections.

Performance of ionic liquid functionalized metal organic frameworks in the adsorption process of phenol derivatives.

The growth of industrial activities has produced a significant increase in the release of toxic organic pollutants (OPs) to the environment from industrial wastewater. On this premise, this study reports the use of metal organic frameworks (MOFs) impregnated with various ionic liquids (ILs) in the adsorption of phenol derivatives, i.e., 2,6-dimethylphenol and 4,4'-dihydroxybiphenyl. MOFs were prepared starting from 1-hydroxyethylidene-1,1-diphosphonic acid (HEDP) with divalent (Co, Ni, Cu) and trivalent (Ce) metal salts in mild hydrothermal conditions using water as a green solvent. Imidazolium base ionic liquids, namely 1-butyl-3-methylimidazolium trifluoromethanesulfonate, 1-butyl-3-methylimidazolium nitrate, 1-butyl-3-methylimidazolium chloride, and 1-hexyl-3-methyl-imidazolium chloride, were used to modify MOFs, leading to composite materials (IL@MOF), which show the structural characteristics of MOFs, and complement the advantages of ILs. SEM, EDX images, and TG data indicate that the IL is just attached on the surface of the adsorbent material, with no changes in crystal size or morphology, but with slightly altered thermal stabilities of IL@MOF composites compared to the original ILs and MOFs, pointing to some interionic interaction between IL and MOF. This research consists of equilibrium experiments, studying the effect of the initial concentration of OPs on the adsorption efficiency of the as-prepared MOFs and IL@MOF, in order to determine the influence of the nature of the adsorbent on its developed adsorption capacity and to investigate the performance of both ILs and MOFs. To determine the maximum adsorption capacity, several empirical isotherms were used: Langmuir, Freundlich, Redlich-Peterson, and Dubinin-Radushkevich. The characteristic parameters for each isotherm and the correlation coefficient (R2) were identified. The IL modification of MOFs increased the adsorption capacity of IL@MOF for the removal of phenol derivatives from aqueous solution. The adsorption capacity function of the MOF structure follows the trend CeHEDP > CoHEDP > NiHEDP > CuHEDP. The best performance was achieved by adsorbent materials based on Ce.

Amino-modified ZIF-8 for enhanced CO2 capture: Synthesis, characterization and performance evaluation

The urgent need for sustainable and innovative approaches to mitigate the increasing levels of atmospheric CO2 necessitates the development of efficient methods for its removal. In this study, we focus on the new, innovative approach for synthesis and functionalization of metal-organic framework (MOF) ZIF-8 in one step at room temperature to enhance its capacity for CO2 capture. Specifically, we investigated the impact of four amino-compounds, namely tetraethylenepentamine (TEPA), hexadecylamine (HDA), ethanolamine (ELA), and cyclopropylamine (CPA), on the chemical structure, size, surface area and porosity, and CO2 capturing of ZIF-8 powder. By varying concentrations of the amino-compounds, we examined their influence on the ZIF-8 properties. Our findings demonstrate that each amino-compound and its respective concentration exhibit distinct effects on the characteristics of ZIF-8. Notably, the ZIF-8 sample functionalized with the highest presented concentration of TEPA exhibited significant improvement in CO2 trapping efficiency, with a 33.3% enhancement. Moreover, least concentrated samples with added HDA or CPA demonstrated notable improvements with enhancements of 46.6% and 18.6%, respectively. These results highlight the potential of simple synthesis and functionalization techniques for MOFs in enhancing their CO2 capture capabilities. The findings from this study offer new opportunities for the development of strategies to mitigate CO2 emissions using MOFs.

Facile preparation of durable superhydrophobic DTMS@HKUST-1 wood membrane for continuous oil-water separation in harsh conditions

Manufacturing durable wood membranes that demonstrate both high efficiency and ultra-high flux for continuous oil-water separation utilizing scalable and cost-effective processes remains a serious challenge. In this study, a facile two-step approach is employed to prepare a novel superhydrophobic/oleophilic wood-based MOF (metal-organic framework) membrane. This method involves in-situ anchoring of the octahedral Cu-HKUST-1 (copper benzene-1,3,5-tricarboxylate) onto the wood sponge (WS), which inherently features internal micro-channels. The structure is then modified using the eco-friendly hydrophobic long-chain coupling agent dodecyltrimethoxysilane (DTMS). Due to its unique micro/nanoscale rough surface morphology and low surface energy, the functional wood membrane (DTMS/HKUST-1@WS) exhibited a high contact angle of 162.98±1.10° for water and was able to effectively separate various immiscible oil/water mixtures. Notably, the DTMS/HKUST-1@WS membrane can be integrated into a pump drive system, serving as an advanced filter element for the sustained and efficient oil-water constituents. Results showed that this membrane possesses attractive permeability toward CCl4 (56689.34 L·m−2·h−1) and toluene (47241.12 L·m−2·h−1), achieving separation efficiencies over 99.0%. Furthermore, this novel membrane exhibits remarkable resistance to physical damage, high/low temperatures, and corrosive solutions, thereby showcasing stable superhydrophobic and superoleophilic interfaces suitable for oily wastewater treatment in harsh environments. Thus, this work offers an innovative approach for designing functional wood-based MOF membranes to achieve highly efficient continuous oil-water separation.

Empowering the Water Oxidation Activity of the Bimetallic Metal-Organic Framework by Annexing Gold Nanoparticles over the Catalytic Surface.

Electrocatalytic water splitting to an anodic oxygen evolution reaction (OER) and a cathodic hydrogen evolution reaction (HER) is believed to be the most important application for sustainable hydrogen generation. Being a four-electron, four-proton transfer process, the OER plays the main obstacle for the same. Therefore, designing an effective electrocatalyst to minimize the activation energy barrier for the OER is a research topic of prime importance. The metal-organic framework (MOF) with a highly porous network is considered an appropriate candidate for the OER in alkaline conditions. Apart from several MOFs, the bimetallic one has an advantageous electrocatalytic performance due to the synergistic electronic interaction between two metal ions. However, most bimetallic MOFs have an obstacle to electrocatalytic application due to their low conductive nature, and therefore, they possess a barrier for charge transfer kinetics at the interface. Surface functionalization via various nanoparticles (NPs) is believed to be the most effective strategy for nullifying the conductive issue. In this work, we have designed a CoNi-based bimetallic MOF that was surface-functionalized by Au NPs (Au@CoNi-Bpy-BTC) for the OER under alkaline conditions. Au@CoNi-Bpy-BTC required an overpotential of just 330 mV, which is 56 mV lower as compared to the pristine MOF. Impedance analysis confirms an improved conductivity and charge transfer at the interface, where Au@CoNi-Bpy-BTC possesses a lower Rct value than CoNi-Bpy-BTC materials. Moreover, the Au-decorated MOF shows an 8.5 times increase in the TOF value compared to the pristine MOF. Therefore, this noble strategy toward the surface functionalization of MOFs via noble metal NPs is believed to be the most effective strategy for developing effective electrocatalysts for electrocatalytic application in energy-related fields. Overall, this report displays an exceptional correlation between the decorated NPs over the MOF surface, which can regulate the OER activity, as confirmed by experimental analysis.

Unlocking the potential of phosphogypsum waste: Unified synthesis of functional metal-organic frameworks and zeolite via a sustainable valorization route

Phosphogypsum (PG) is one of the hazardous wastes generated during phosphate fertilizers production. Valorizing PG into value-added materials is needed to overcome the environmental threat of accumulating PG stockpiles. The primary chemical constituents of PG are CaSO4·2H2O, SiO2, Al2O3, P2O5, and trace metals. Herein, we employed unified strategic synthesis method to transform the main components of PG into two classes of functional porous materials in subsequent steps. The alumina and silica components were isolated to fabricate cancrinite zeolite (CAN) while the residual calcium was directed to grow Ca-based metal–organic frameworks (Ca-MOFs) in the subsequent step. The resulting zeolite with a Si/Al ratio of ∼2.2 showed enhanced CO2 capture property, which, in many respects, is better than those achieved by similar frameworks from other precursors. The unveiled MOF synthesis approach was proven to be adaptable, allowing the preparation of different Ca-MOFs from organic linkers of diverse connectivity, namely Ca-BDC, Ca-BTC, and Ca-TCPB (SBMOF-2), using the linear ditopic benzene dicarboxylate, the tritopic benzene tricarboxylate, and tetracarboxylate-based linkers, respectively. The successful assembly of the porous materials was confirmed using various characterization techniques, including XRD, SEM-EDX, FTIR, and TGA-MS. The porosity of the materials was also probed using N2 at 77 K, CO2 at different temperatures, and H2O at 298 K sorption analyses. The Ca-BTC MOF with the optimal pore aperture size (∼3.4 Å) shows a potential for water/alcohol separation with a steep and fast moisture adsorption profile and negligible alcohol uptake. The synthetic transformation approach presented in this work represents the first example of a valorization route to form extended porous structures from PG waste.

Synthesis of pH responsive malononitrile functionalized metal organic framework MIL-100(Fe) for efficient adsorption of uranium U(VI) from real-life alkaline leach liquor

The porous framework of MIL-100(Fe) was functionalized using malononitrile (MN), through an in-situ Knoevenagel condensation reaction to introduce abundant –CN groups on the surface of the developed adsorbent. The resultant MN-functionalized MIL-100(Fe) exhibited excellent Uranium (U(VI)) removal capacity (i.e., 270 mg/g) at highly alkaline pH (⁓ 10). Different coexisting cations and anions show negligible influence on the U-removal and it was 92.1–99.7 % in presence of different co-ions, with the concentration from 10 to 50 mg/L. Moreover, MIL-100(Fe)_MN showed extremely selective U removal from the actual alkaline leach liquor (⁓ 97 %), without any pH adjustment and leaching of the constituent Fe. The surface-grafted –CN groups were predominantly active towards the coordinative interactions with the U(VI) ionic moieties, as evident from the XPS and FTIR analysis. The MIL-100(Fe)_MN adsorbent was also subjected to five consecutive adsorption-desorption cycles, with >90 % U removal after 5th cycle. Moreover, the regenerated MIL-100(Fe)_MN was structurally and functionally resilient, as observed from the morphological and crystallographic analysis. A convection-pore diffusion based transport model was used to analyze the optimized mass transfer parameters. Overall, the present study highlights the simple design and development of malononitrile-functionalized MIL-100(Fe) as an efficient and selective adsorbent for U(VI) removal from U-rich alkaline leach liquor.

Monitoring of Sweat pH and Dual‐Mode Anti‐Counterfeiting from Metal‐Organic Framework‐Based Multifunctional Gel

Comprehensive SummaryMonitoring of sweat pH plays important roles in physiological health, nutritional balance, psychological stress, and sports performance. However, the combination of functional MOFs with phosphorescent material to acquire the real‐time physiological information, as well as the application of dual mode anti‐counterfeiting, has seldom been reported. Herein, we developed multifunctional gel films based on MOFs and phosphorescent dyes which responded to H+ ions and the related mechanism was studied in detail. Upon exposure to H+, the composite gel film exhibited decreased fluorescent signal but enhanced room temperature phosphorescence (RTP), which could be utilized for sweat pH sensing through a dual‐mode. Moreover, multifunctional gel films exhibited a potential application in information encryption and anti‐counterfeiting by designing of stimulus responsive multiple patterns. This research provided a new avenue for portable and non‐invasive sweat pH monitoring methods while also offering insights into stimulus‐responsive multifunctional materials.

Construction of a polydopamine-MnO2 functionalized metal–organic framework for synergistic photothermal/NO/nanocatalytic antibacterial therapy

In this study, a multifunctional antibacterial platform was constructed that integrates photothermal/ NO/ nanocatalytic therapy by polydopamine (PDA)-MnO2 functionalized metal–organic framework with loading of NO precursor (NO@MOF@ PMnO2). The PDA coating imbues the nanoplatforms with photothermal performance. Furthermore, the heat generated from NIR could trigger a NO release, further augmenting the antibacterial activity. Moreover, the presence of the MnO2 component, which serves as a peroxidase nanozyme, catalyzes the enzymatic decomposition of H2O2 to generate hydroxyl radicals (·OH), increasing the permeability of the bacterial cell membrane and its sensitivity to heat and NO. As a result, the nanoplatform possesses an outstanding antibacterial performance against S. aureus and E. coli under the NIR laser. Therefore, the present study presents a photothermal/NO/nanocatalytic platform for synergistic antibacterial therapy.

Colorimetric strategy of Fe/Co-doped porphyrin metal-organic frameworks with enzyme-like activity for the detection of ascorbic acid

The multifunctional structures and functions of metal-organic frameworks with enzyme-like activity make them promising for various applications. This study has shown Fe/Co-doped porphyrin metal-organic framework (PCN-224-Fe/Co) (PCN-224 = porous coordination network-224) efficiently catalyzed the substrates hydrogen peroxide (H2O2) and 3,3′,5,5′-tetramylbenzidine (TMB) to generate oxidized-TMB (oxTMB). The results of the kinetic experiments showed that PCN-224-Fe/Co had a greater affinity for TMB compared to PCN-224-Fe or PCN-224-Co. A selective colorimetric method for determining ascorbic acid (AA) was also successfully developed due to the peroxidase-like activity of PCN-224-Fe/Co. The linear concentration-response range was found to be between 1 and 200 μM with a detection limit of 0.2 μM. This research will facilitate the creation of peroxidase mimics utilizing porphyrin metal-organic frameworks for use in detective applications.

Metal organic framework doped amine-functionalized polymeric beads for selective removal of Uranium (VI) from alkaline leach liquor: Batch and column study

In this work, a diethylenetriamine (DETA) functionalized metal organic framework (ZIF-67) incorporated polyacrylonitrile (PAN) bead (MFB) was developed to capture U efficiently from simulated medium and alkaline leach liquor. The synthesized beads were characterized using suitable analytical methods. Fourier transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS) were used to understand the U uptake mechanism. The process of adsorption was inherently heat-absorbing and spontaneous in nature. The Langmuir sorption capability (Qm) was 835 mg/g, at pH 7 and, 298 K. Surface- grafted abundant amine (–NH2) groups introduce significant coordinative interaction with the U species in aqueous medium. The adsorbent is reusable and structurally robust with >85 % U removal after five consecutive regeneration cycles. The performance of the continuous adsorption columns was simulated by a fundamental adsorption-diffusion model and the relevant transport parameters were evaluated. For real life alkaline leach liquor with U concentration 825 mg/L and 100 to 500 kg of adsorbent, the adsorption column had a breakthrough life of 46 to 108 days with constant flow rate of 500 L/day. This study showed that the synthesized MFB is an excellent adsorbent that is inexpensive, non-toxic, recyclable,environmentally compatible, and selective towards U removal from alkaline leach liquor.

Bionic Mineralization toward Scalable MOF Films for Ampere-Level Biomass Upgrading.

With significant advances in metal-organic framework (MOF) nanostructure preparation, however, the facile synthesis of large-scale MOF films with precise control of the interface structure and surface chemistry is still challenging to achieve with satisfactory performance. Herein, we introduce a universal strategy bridging metal corrosion chemistry and bionic mineralization to synthesize 16 MOF films on 7 metal supports under ambient conditions. The robustness to explore unlimited libraries of MOF films (e.g., carboxylate-, N-heterocycle-, phenolic-, and phosphonate-MOFs) on supports is evoked by independently regulating the metal redox behavior, electrolyte properties, and organic ligands along with hydrogen evolution or oxygen reduction, which offers the basic guidelines for regulating the microstructure and composition of MOFs on the Pourbaix diagram. In conjunction with multiple manufacturing methods, we demonstrated proof of concept for "printing" a large variety of MOF patterns from micrometer to meter scales. Furthermore, a large-area electrolyzer (64 cm2) devised enables 5-hydroxymethylfurfural oxidation to achieve a record-breaking current of 3.0 A at 1.63 V with 2,5-furandicarboxylic acid production, leading to the simultaneous production of H2 gas and valuable feedstocks. The improved electrocatalytic activity for significantly boosting the 5-hydroxymethylfurfural oxidation exemplifies one of the functional MOF films for given applications beyond biomass upgrading.

Enabling simultaneous valorization of tannery effluent and waste plastic via sustainable preparation of Cr-BDC MOFs for water adsorption

Advanced materials undergo a complex and lengthy process of maturation for scaling up and deployment, mainly due to the high cost of their precursors. Therefore, it is highly desirable to fabricate highly valuable advanced porous solid-state materials, with proven applicability, by sustainably combining organic and inorganic waste materials as precursors. This study successfully demonstrates the preparation of Cr-terephthalate Metal–Organic Frameworks (Cr-BDC MOFs) by combining metal salt and organic linker extracted from tannery effluent and waste plastic bottles. The waste from tanneries was used as the source of Cr(III), while terephthalic acid was obtained from the alkaline hydrolysis of plastic bottles. Appropriate extraction and assembly processes led to the functional Cr-BDC MOFs, MIL-101(Cr) and MIL-53(Cr). The prepared MOFs showed similar properties (surface area, hydrolytic and thermal stability, and water adsorption performance) to similar MOFs synthesized from pure commercial-grade precursors, as confirmed by N2 sorption, XRD, TGA, and water adsorption experiments. The advancements made in this study represent significant progress in overcoming the bottleneck of MOF production cost efficiency via applying sustainability principles and pave the way for easy scaling-up and maturation of MOF-based processes, for air dehumidification and water harvesting as a case study.

Electrochemical deposition of Pyrazine-Templated 2D Ru@MOFs nanosheets for sensitive electrochemiluminescent immunoassay of classical swine fever virus

Electrochemical deposition technique for room-temperature fabrication of functionalized metal–organic frameworks (MOFs) have attracted increasing attention in many important applications. Herein, a sensitive electrochemiluminescent (ECL) immunosensor was fabricated for the determination of classical swine fever virus (CSFV) based on electrochemical synthesis and deposition of pyrazine-templated ruthenium (II)-MOFs (Pyz-Ru@MOFs) thin films on the electrode surface. In this protocol, the 2D Pyz-Ru@MOFs nanosheets were synthesized under green water phase condition from the carboxyl-rich tris(4,4′-dicarboxylic acid-2,2′-bipyridyl) ruthenium(II) (Ru(dcbpy)32+) as ECL luminophore and organic ligand to coordinate with zinc ions, and pyrazine as a structure-directing agent to control the formation of sheetlike structure. Due to packaging plenty of Ru(dcbpy)32+ molecules in the frameworks, the mesoporous thin films of Pyz-Ru@MOFs exhibited excellent ECL performance. Using this 2D Pyz-Ru@MOFs as a sensing platform, a “signal-off” ECL immunosensor was constructed for CSFV analysis, which displayed high sensitivity and good selectivity for CSFV detection in the range of 10 fg mL−1 –10 ng mL−1 with a detection limit of 5.4 fg mL−1. In addition, the prepared immunosensor was successfully utilized for the satisfactory detection of CSFV in serum samples, which has potential application in biological analysis and clinical diagnosis. This proposed woke also provided a simple and feasible electrochemical synthesis strategy to construct 2D luminescent MOFs immobilized ECL luminophores, offering significant inspiration to develop highly efficient ECL materials at room temperature with ECL sensing applications.

Comparative study of different metal-organic framework electrodes synthesized using waste PET bottles for supercapacitor applications

The conversion of plastic waste into high-value metal-organic framework (MOF) materials has currently grabbed the attention as an important research area for mitigating environmental and economic issues. Due to their large surface area and high porosity, MOFs have a significant advantage as supercapacitor electrode material. In this study, MOFs (Cu-MOF, Zr-MOF, and Ti-MOF) were produced from plastic wastes (PET bottles) using hydrothermal approach. These MOFs were tested electrochemically in 1 M H2SO4 electrolyte using three-electrode setup. Among them, Cu-MOF (104.8 F/g at 0.5 A/g) showed higher capacitance and increased diffusion contribution (78.4 %) than its counterparts Zr-MOF (70.5 F/g at 0.5 A/g; 70.4 %) and Ti-MOF (55.5 F/g at 0.5 A/g; 67.5 %). Further, solid-state symmetrical supercapacitor devices have been assembled using all the plastic wastes derived MOFs viz. Cu-MOF//Cu-MOF, Zr-MOF//Zr-MOF, and Ti-MOF//Ti-MOF. Among them, Cu-MOF//Cu-MOF symmetric supercapacitor device performed better than the others by rendering energy density of 18.2 Wh/kg at 825 W/kg power density along with a cyclic stability of 87 % after 10,000 charge-discharge cycles. These studies open new avenues to utilize waste PET bottles to synthesize high functional MOFs for next generation supercapacitors.

Modified Metal Organic Frameworks Supported Ni Single Atom Catalyst for Enhanced Photocatalytic Hydrogen Evolution Reaction

Downsizing metal nanoparticle catalysts to form single-atom catalysts (SACs) has proven to be one of the best ways to enhance the catalysts’ activity and selectivity1-2 due to their unique characteristics such as nearly 100% atom utilization and well-defined active sites.3 However, the broad application of SACs in catalytic reactions is limited by their poor stability as they possess high surface energy and thus tend to aggregate and form nanoclusters or nanoparticles.4 To address this challenge, various supports such as metal oxides, carbon materials, and porous materials are widely used to stabilize the SACs.5 Metal organic frameworks (MOFs), a class of porous crystalline materials, have proven to be an ideal candidate to support SACs owing to their high surface area, high porosity, and abundant potential anchoring sites.6 It has been shown that immobilizing SACs on MOFs, which forms MOF supported SACs, can integrate the unique properties of SACs and MOFs and led to remarkable catalytic activity, selectivity, and stability toward various catalytic reactions.6-8 Application of MOF supported SACs in photocatalysis, organic linkers of metal-organic frameworks act as photosensitive units,9 However most pristine metal-organic frameworks possesses poor light absorption properties due to wide band gap.9To enhance the light harvesting properties of the metal organic framework its organic linker is functionalized.10-11 In my poster presentation, I will present my work where post-synthetic modification of UiO-66-NH2 MOF linker with 3,4,9,10 perylene tetracarboxylic dianhydride (PDA) an organic molecule with broad absorption edge,12and immobilization of Ni single atom catalyst on the zirconium cluster of the MOF was done. This resulted in enhanced optical properties and charge separation efficiency which was proved by a combination of UV-visible spectroscopy (UV-Vis), photoelectrochemical techniques, and X-ray absorption spectroscopy (XAS). Observed photophysical effects posed by the modifications of the UiO-66-NH2 were evaluated by photocatalytic hydrogen generation.References Yan, J.; Kong, L.; Ji, Y.; White, J.; Li, Y.; Zhang, J.; An, P.; Liu, S.; Lee, S.-T.; Ma, T., Single atom tungsten doped ultrathin α-Ni (OH) 2 for enhanced electrocatalytic water oxidation. Nature communications 2019, 10 (1), 1-10.Jiao, L.; Jiang, H.-L., Metal-organic-framework-based single-atom catalysts for energy applications. Chem 2019, 5 (4), 786-804.Qiao, B.; Wang, A.; Yang, X.; Allard, L. F.; Jiang, Z.; Cui, Y.; Liu, J.; Li, J.; Zhang, T., Single-atom catalysis of CO oxidation using Pt1/FeO x. Nature chemistry 2011, 3 (8), 634-641.Xia, C.; Qiu, Y.; Xia, Y.; Zhu, P.; King, G.; Zhang, X.; Wu, Z.; Kim, J. Y.; Cullen, D. A.; Zheng, D., General synthesis of single-atom catalysts with high metal loading using graphene quantum dots. Nature chemistry 2021, 13 (9), 887-894.Wu, J.; Xiong, L.; Zhao, B.; Liu, M.; Huang, L., Densely populated single atom catalysts. Small Methods 2020, 4 (2), 1900540.Huang, H.; Shen, K.; Chen, F.; Li, Y., Metal–organic frameworks as a good platform for the fabrication of single-atom catalysts. ACS Catalysis 2020, 10 (12), 6579-6586.Qu, W.; Chen, C.; Tang, Z.; Wen, H.; Hu, L.; Xia, D.; Tian, S.; Zhao, H.; He, C.; Shu, D., Progress in metal-organic-framework-based single-atom catalysts for environmental remediation. Coordination Chemistry Reviews 2023, 474, 214855.Szilágyi, P.; Rogers, D.; Zaiser, I.; Callini, E.; Turner, S.; Borgschulte, A.; Züttel, A.; Geerlings, H.; Hirscher, M.; Dam, B., Functionalised metal–organic frameworks: a novel approach to stabilising single metal atoms. Journal of Materials Chemistry A 2017, 5 (30), 15559-15566.He, J.; Wang, J.; Chen, Y.; Zhang, J.; Duan, D.; Wang, Y.; Yan, Z., A dye-sensitized Pt@ UiO-66 (Zr) metal–organic framework for visible-light photocatalytic hydrogen production. Chemical communications 2014, 50 (53), 7063-7066.Elcheikh Mahmoud, M.; Audi, H.; Assoud, A.; Ghaddar, T. H.; Hmadeh, M., Metal–Organic Framework Photocatalyst Incorporating Bis(4′-(4-carboxyphenyl)-terpyridine)ruthenium(II) for Visible-Light-Driven Carbon Dioxide Reduction. Journal of the American Chemical Society 2019, 141 (17), 7115-7121.Hendrickx, K.; Joos, J. J.; De Vos, A.; Poelman, D.; Smet, P. F.; Van Speybroeck, V.; Van Der Voort, P.; Lejaeghere, K., Exploring lanthanide doping in UiO-66: a combined experimental and computational study of the electronic structure. Inorganic Chemistry 2018, 57 (9), 5463-5474.Yu, H.; Joo, P.; Lee, D.; Kim, B. S.; Oh, J. H., Photoinduced Charge‐Carrier Dynamics of Phototransistors Based on Perylene Diimide/Reduced Graphene Oxide Core/Shell p–n Junction Nanowires. Advanced Optical Materials 2015, 3 (2), 241-247.

(Invited) Grahame Symposium: Separating and Moving Charges through Functional Metal-Organic Frameworks

In line with the longstanding physical electrochemistry interests and numerous innovative contributions of Grahame Award recipient Dr. Keith Stevenson, this presentation will focus on a physical electrochemistry problem: how to separate redox-hopping based hole-transport within porous, electrocatalytic metal-organic framework coatings from transport of charge-compensating ions through the same coatings. In principle, either process, or both, could define transport rates. For electrocatalysis, the general goal is to achieve the fastest transport possible. Wall-jet electrochemistry – the approach used here – offers a useful way of assessing redox-hopping rates without complications from ion ingress or egress. The wall-jet approach turns out to be especially useful when samples cannot be made compatible with RDE or IDE assemblies.

Coordination Bonding Directed Molecular Assembly toward Functional Metal–Organic Frameworks: From Structural Regulation to Properties Modulation

Coordination Bonding Directed Molecular Assembly toward Functional Metal–Organic Frameworks: From Structural Regulation to Properties Modulation