MOF-derived Materials Research Articles

Spectroelectrochemistry: A Powerful Tool for Studying Fundamental Properties and Emerging Applications of Solid-State Materials Including Metal–Organic Frameworks

Spectroelectrochemistry (SEC) encompasses a broad suite of electroanalytical techniques where electrochemistry is coupled with various spectroscopic methods. This powerful and versatile array of methods is characterised as in situ, where a fundamental property is measured in real time as the redox state is varied through an applied voltage. SEC has a long and rich history and has proved highly valuable for discerning mechanistic aspects of redox reactions that underpin the function of biological, chemical, and physical systems in the solid and solution states, as well as in thin films and even in single molecules. This perspective article highlights the state of the art in solid-state SEC (ultraviolet–visible–near-infrared, infrared, Raman, photoluminescence, electron paramagnetic resonance, and X-ray absorption spectroscopy) relevant to interrogating solid state materials, particularly those in the burgeoning field of metal–organic frameworks (MOFs). Emphasis is on developments in the field over the past 10 years and prospects for application of SEC techniques to probing fundamental aspects of MOFs and MOF-derived materials, along with their emerging applications in next-generation technologies for energy storage and transformation. Along with informing the already expert practitioner of SEC, this article provides some guidance for researchers interested in entering the field.

Cu-based MOF-derived porous carbon with highly efficient photothermal conversion performance for solar steam evaporation

MOF-derived carbon nanostructure photothermal materials have shown remarkable potential in solar steam generation due to their excellent light absorption properties, high chemical stability and considerable photothermal conversion efficiency.

MOF(ZM)/Potassium Citrate-Derived Composite Porous Carbon and Its Electrochemical Properties

Metal-organic frameworks are compounds with a reticulated skeletal structure formed by chemically bonding inorganic and organic units that are widely used in many fields, such as photocatalysis, gas separation and energy storage, because of their unique structures. In this paper, we prepared a metal-organic framework [(μ2-2-methylimidazolyl)12-Zn(ii)6-H18O10]n(ZM) with well-developed pores and high specific surface area of MOFs by the solution method. And MOF-derived porous carbon was prepared by the direct charring method in an argon atmosphere using a mixture of ZM, ZM and potassium citrate as carbon precursors. Characterization analysis revealed that the maximum specific surface area of ZMPC-800-1:15 was 2014.97 m2⋅g−1, and the pore size structure was mainly mesoporous. At a current density of 1.0 A⋅g−1 the specific capacitance of ZMC-800 and ZMPC-800-1:15 was 121.3 F⋅g−1 and 226.6 F⋅g−1, respectively, with a substantial increase of 86.8%. The specific capacitance of ZMPC-800-1:15 decays to 168.8 F⋅g−1, with a decay rate of 25.5%, when the current density increases to 10.0 A⋅g−1. After 5000 constant current charge/ discharge cycles, the capacitance retention rate was still 96.41%. These results prove that the application of MOF-derived carbon materials in future supercapacitors is very promising.

A review on metal-organic framework-derived anode materials for potassium-ion batteries.

In recent years, metal-organic frameworks (MOFs) have been widely used in the field of electrochemical energy storage and conversion because of their excellent properties, such as high specific surface area, adjustable pore size, high porosity, structural diversity, and functional controllability. This paper reviews the applications of metal-organic framework-derived composites such as nitrogen-doped carbon, transition metal sulfides, transition metal selenides, transition metal phosphides and metal selenium compound modifications in potassium ion batteries (PIBs) as anode electrode materials. A variety of MOF-derived composites with different structures and morphologies based on several types of ligands, including 2-methylimidazole, aromatic carboxylic acids, and ferricyanide, have been discussed. Moreover, the current challenges faced by MOF-derived materials and possible countermeasures are proposed.

Fabrication of Ni–MOF-derived composite material for efficient electrocatalytic OER

The poverty-stricken population cannot withstand the shocks of global warming and can hardly pay the soaring expenditure of fossil fuels whose reservoirs are already approaching the threshold limit. These adventures guided the researchers towards water oxidation as a source of energy. In this study, a metal-organic framework (MOF)-based material was fabricated and catalyzed the lethargic oxygen evolution reaction (OER). The synthesized material is characterized with different analytical techniques to confirm structural, morphological and textural properties. Its huge surface area (87 m2/g) rendered it a promising material to carry the OER. It exhibited shallow onset potential that is, 1.40 V vs. RHE and displayed an exceptionally low overpotential of 1.42 V vs. RHE to reach the benchmark current density (10 mA/cm2) with remarkably small Tafel slope that is, 34 mV/dec. It surpassed the state of the art electrocatalyst for OER, that is, IrO2 and RuO2 in efficiency as well as in stability.

2D metal-organic framework-based materials for electrocatalytic, photocatalytic and thermocatalytic applications.

Ultrathin two-dimensional metal-organic frameworks (2D MOFs) have recently attracted extensive interest in various catalytic fields (e.g., electrocatalysis, photocatalysis, thermocatalysis) due to their ultrathin thickness, large surface area, abundant accessible unsaturated active sites and tunable surface properties. Besides tuning the intrinsic properties of pristine 2D MOFs by changing the metal nodes and organic ligands, one of the hot research trends is to develop 2D MOF hybrids and 2D MOF-derived materials with higher stability and conductivity in order to further increase their activity and durability. Here, the synthesis of 2D MOF nanosheets is briefly summarized and discussed. More attention is focused on summaries and discussions about the applications of these 2D MOFs, their hybrids and their derived materials as electrocatalysts, photocatalysts and thermocatalysts. The superior properties and catalytic performance of these 2D MOF-based catalysts compared to their 3D MOF counterparts in electrocatalysis, photocatalysis and thermocatalysis are highlighted. The enhanced activities of 2D MOFs, their hybrids and derivatives come from abundant accessible active sites, a high density of unsaturated metal nodes, ultrathin thickness, and tunable microenvironments around the MOFs. Views regarding current and future challenges in the field, and new advances in science and technology to meet these challenges, are also presented. Finally, conclusions and outlooks in this field are provided.

Recent progress in development of efficient electrocatalyst for methanol oxidation reaction in direct methanol fuel cell

The human craving for energy is continually mounting and becoming progressively difficult to Gratify. At present, the world's massive energy demands are chiefly encountered by nonrenewable and benign fossil fuels. However, the development of dynamic energy cradles for a gradually thriving world to lessen fossil fuel reserve depletion and environmental concerns are persistent issues for society at present. The discovery of copious nonconventional resources to fill the gap between energy petition and supply is the extreme obligation of the modern era. A new emergent, clean, and robust alternate of fossil fuels are the fuel cells. Among the different types of fuel cells, direct methanol fuel cells are an outstanding option for light-duty vehicles and portable devices. A critical tactic for striving and sustainable energy sources is the production of highly proficient, economical, and green catalysts for energy storage and conversion devices. Up till now a broad range of research work is available to use Pt and modify Pt-based electrocatalysts to augment the CH3OH oxidation process. Platinum-based nanocubes, nanorods, nanoflower, hybrids of Pt with metal-oxides such as Fe2O3, TiO2, SnO2, MnO, Cu2O, ZnO, and with conducting polymers are extensively utilized in both acidic and basic media. Moreover, Pd-based materials, transition metal-based materials as well as MOF and MOF-derived materials are also the point of interest for researchers nowadays. However, the problem associated with their practical applications is that they can be effectively employed in basic media due to comparative less stability in acidic medium. This review article will deliver a broad vision of the current progress of the MOR process concerning noble metals, transition metals, and MOF-based materials.

1D-3D mixed-dimensional MnO2@nanoporous carbon composites derived from Mn-metal organic framework with full-band ultra-strong microwave absorption response

Nano-porous carbon (NPC) composites derived from metal-organic frameworks (MOFs) possess effective microwave absorption (MA) properties. However, the fabrication of MOF-derived NPC composites with full-band MA performance is challenging. In this work, the effect of the bandgap on the microwave dielectric behavior of Mn-MOF derivatives was investigated. The results demonstrated that a narrower MnO2 bandgap resulted in higher conductivity and a larger dielectric constant of the corresponding materials. The three-dimensional (3D) [email protected] composites achieved excellent low-frequency MA ability. The maximum reflection loss (RL) of [email protected] carbonized at 800 °C reached −54.38 dB at 5.12 GHz. The 1D-3D mixed-dimensional MnO2@NPC composites with the ultra-strong MA response in the full band were obtained by oxidizing [email protected] to MnO2@NPC. MnO2@NPC-800 showed superior MA capacity with the maximum RL value equal to −63.21 dB at 12.48 GHz and 2.05 mm thickness. The maximum RL values in S, C, X, Ku bands also exceeded −50 dB. Such an outstanding MA performance of MnO2@NPC-800 composite was attributed to the MnO2 presence and its multi-dimensional structure. This work provides the foundation for the fabrication of MOF-derived materials capable of full-band MA.

Metal-Organic Framework Derived Bimetallic Materials for Electrochemical Energy Storage.

Supercapacitors (SCs), showing excellent power density, long service life, and high reversibility, have received great attention because of the increasing demand for energy storage devices. To further improve their performance, it is essential to develop advanced electrode materials. One group of materials, porous crystalline solids referred to as metal-organic frameworks (MOFs), have proved to be excellent templates for synthesizing functional materials to be employed in the preparation of electrodes for SCs. In comparison to monometallic MOFs, bimetallic MOFs and their derivatives offer a number of advantages, including tunable electrochemical activity, high charge capacity, and improved electrical conductivity. This review focuses on the use of MOF-derived bimetallic materials in SCs, the origin of the improved performance, and the latest developments in the field. Furthermore, the challenges and perspectives in this research area are discussed.

Bimetallic metal-organic framework derived porous NiCo2S4 nanosheets arrays as binder-free electrode for hybrid supercapacitor

Recently, metal-organic frameworks (MOFs) derived materials in the form of bulk powders with attractive chemical and structural properties show broad application in electrochemical energy storage. Bimetallic materials-based MOFs usually show better electrochemical properties than that of monometallic derivatives, while achieving the bimetallic MOFs-derived materials on current collector as a binder-free electrode is still a challenge. Here we report a new approach to directly obtain a binder-free electrode of bimetallic MOFs-derived NiCo2S4 nanosheet arrays on nickel foam (NF) substrate. The porous NiCo2S4 nanosheet arrays providing fast electrolyte permeation and rich electrochemical active sites, show an excellent specific capacity of 1354.4 C g−1, high rate performance, and outstanding cycling stability of 82.6% retention after 10,000 cycles. A hybrid supercapacitor assembled with the as-obtained binder-free electrode as a cathode and active carbon as an anode, exhibits high energy density of 49.1 Wh kg−1 at a power density of 375 W kg−1 and superior cycling stability of 94.5% retention after 10,000 cycles. These results offer a novel and general approach to construct binder-free electrode materials with advanced performance for the portable and practical energy storage device.

Recent advances in lithium-based batteries using metal organic frameworks as electrode materials

Metal organic frameworks (MOFs) show excellent electrochemical performances due to their ultrahigh porosity, large specific surface area, and easy functionalization. These characteristics make it fascinating electrode materials with excellent electrochemical performance for the currently dominated lithium-based batteries (e.g., Li-ion batteries, Li-S batteries, Li-O2 batteries). Hence, this review summarizes the recent advances of MOFs-based materials as an electrode for high-performance lithium-ion storage. Firstly, we briefly describe the development history, principle, and mechanism of the lithium-based batteries. Then, the recent advances of MOFs/MOFs composite and MOF-derived materials employed as electrode materials for Lithium-ion batteries, Li-S batteries, and Li-O2 batteries are reviewed with their electrochemical performances. Finally, we conclude and point out the future direction of MOFs-related materials for lithium-based batteries.

Metal-organic framework derived NiCoP hollow polyhedrons electrocatalyst for pH-universal hydrogen evolution reaction

Hollow nanostructures have attracted increasing research interest in hydrogen evolution reaction owing to their unique structural features. Herein, Ni–Co mixed metal phosphide hollow and porous polyhedrons was successfully composited (expressed as NiCoP). Benefiting from the synergistic effects of ZIF-67 by doping Ni elements and the well-defined hollow and porous structure, the as-synthesized NiCoP hollow and porous polyhedrons exhibit better electrochemical properties and mechanical stability for hydrogen evolution reaction over a pH-universal range, with a small Tafel slopes of 72, 101, 176 mV/dec, and a low overpotential of 82, 102, 261 mV at a current density of 10 mA/cm2 in 0.5 mol/L H2SO4, 1 mol/L KOH and 1 mol/L phosphate buffer solution (PBS). This general strategy can also be applied to fabricate other hollow cobalt-based phosphides and MOFs-derived materials for HER.

Enhanced microwave absorption of epoxy composite by constructing 3D Co–C–MWCNTs derived from metal organic frameworks

In this study, a magnetic/dielectric composite precursor is obtained by in situ growing zeolitic imidazolate framework-67 nanoparticles on the surface of acidified multi-walled carbon nanotubes (MWCNTs). After pyrolyzing the precursor in an argon atmosphere, a kind of nano-heterogeneous composite wave absorber was prepared. Subsequently, a new type of magnetic/dielectric wave-absorbing composite was prepared by heating and curing Co–C–MWCNTs and epoxy resin, and the properties of the composite were adjusted by changing the content of Co–C–MWCNTs. A variety of modern characterization methods were used to systematically study the micro-morphology, element composition and electromagnetic properties of the composite. The results show that after the combination of MWCNTs and Co–C particles with regular dodecahedron structure, a special synergistic effect appears. The addition of magnetic MOF derivatives not only improves the impedance matching characteristics of the composite and increases the magnetic loss mechanism, but also provides a new path for the transmission of electromagnetic waves because of its special pore structure and the three-dimensional network structure formed by cross-linking with MWCNTs. The interface polarization and multiple scattering effects greatly improve the attenuation efficiency of electromagnetic waves. In X-band (8–12 GHz), the Co–C–MWCNTs/EP composite with a loading of 17.5 wt% can achieve an effective absorption bandwidth of 2.38 GHz when the matching thickness is 1.6 mm. The combination of novel MOF-derived materials and traditional carbon materials is expected to provide new ideas for the design of composites with microwave absorption capabilities.

Highly N/O co-doped ultramicroporous carbons derived from nonporous metal-organic framework for high performance supercapacitors

A new nonporous Zn-based metal-organic framework (NPMOF) synthesized from a high nitrogen-containing rigid ligand was converted into porous carbon materials by direct carbonization without adding additional carbon sources. A series of NPMOF-derived porous carbons with very high N/O contents (24.1% for NPMOF-700, 20.2% for NPMOF-800, 15.1% for NPMOF-900) were prepared by adjusting the pyrolysis temperatures. The NPMOF-800 fabricated electrode exhibits a high capacitance of 220 F/g and extremely large surface area normalized capacitance of 57.7 μF/cm2 compared to other reported MOF-derived porous carbon electrodes, which could be attributed to the abundant ultramicroporosity and high N/O co-doping. More importantly, symmetric supercapacitor assembled with the MOF-derived carbon manifests prominent stability, i.e., 99.1% capacitance retention after 10,000 cycles at 1.0 A/g. This simple preparation of MOF-derived porous carbon materials not only finds an application direction for a variety of porous or even nonporous MOFs, but also opens a way for the production of porous carbon materials for superior energy storage.

Metal-Organic Framework Materials for Perovskite Solar Cells.

Metal-organic frameworks (MOFs) and MOF-derived materials have been used for several applications, such as hydrogen storage and separation, catalysis, and drug delivery, owing to them having a significantly large surface area and open pore structure. In recent years, MOFs have also been applied to thin-film solar cells, and attractive results have been obtained. In perovskite solar cells (PSCs), the MOF materials are used in the form of an additive for electron and hole transport layers, interlayer, and hybrid perovskite/MOF. MOFs have the potential to be used as a material for obtaining PSCs with high efficiency and stability. In this study, we briefly explain the synthesis of MOFs and the performance of organic and dye-sensitized solar cells with MOFs. Furthermore, we provide a detailed overview on the performance of the most recently reported PSCs using MOFs.

Recent progress of advanced anode materials of lithium-ion batteries

The rapid development of electric vehicles and mobile electronic devices is the main driving force to improve advanced high-performance lithium ion batteries (LIBs). The capacity, rate performance and cycle stability of LIBs rely directly on the electrode materials. As far as the development of the advanced LIBs electrode is concerned, the improvement of anode materials is more urgent than the cathode materials. Industrial production of anode materials superior to commercial graphite still faces some challenges. This review sets out the most basic LIBs anode material design. The reaction principles and structural design of carbon materials, various transition metal oxides, silicon and germanium are summarized, and then the progress of other anode materials are analyzed. Due to the rapid development of metal organic frameworks (MOFs) in energy storage and conversion in recent years, the synthesis process and energy storage mechanism of nanostructures derived from MOF precursors are also discussed. From the perspective of novel structural design, the progress of various MOFs-derived materials for alleviating the volume expansion of anode materials is discussed. Finally, challenges for the future development of advanced anode materials for LIBs will be considered.

Progress of MOF-Derived Functional Materials Toward Industrialization in Solar Cells and Metal-Air Batteries

The cutting-edge photovoltaic cells are an indispensable part of the ongoing progress of earth-friendly plans for daily life energy consumption. However, the continuous electrical demand that extends to the nighttime requires a prior deployment of efficient real-time storage systems. In this regard, metal-air batteries have presented themselves as the most suitable candidates for solar energy storage, combining extra lightweight with higher power outputs and promises of longer life cycles. Scientific research over non-precious functional catalysts has always been the milestone and still contributing significantly to exploring new advanced materials and moderating the cost of both complementary technologies. Metal-organic frameworks (MOFs)-derived functional materials have found their way to the application as storage and conversion materials, owing to their structural variety, porous advantages, as well as the tunability and high reactivity. In this review, we provide a detailed overview of the latest progress of MOF-based materials operating in metal-air batteries and photovoltaic cells.

Laser Synthesis of MOF-Derived Ni@Carbon for High-Performance Pseudocapacitors.

Although nanosizing of multiphase pseudocapacitive nanomaterials could dramatically improve their electrochemical properties, a proper way to simultaneously control both the size and the phase of the pseudocapacitive materials is still elusive. Herein, we employed a commercial CO2 laser engraver to do the transformation of a metal-organic framework (MOF-74(Ni)) into size-controlled Ni nanoparticles (4-12 nm) in porous carbon. The produced Ni@carbon hybrid showed the best specific capacitance of 925 F/g with excellent cycling stability when the particle size is 5.5 nm. We found that the highly redox-active α-Ni(OH)2 is more predominantly formed than the less redox-active β-Ni(OH)2 as the particle size becomes smaller. Our results substantiate that various MOFs could be created into high-performance pseudocapacitive materials with the controlled size and phase. It is believed that the laser-based synthesis could also serve as a powerful tool for the discovery of new MOF-derived materials in the field of energy storage and catalysis.

In situ encapsulated Co/MnOx nanoparticles inside quasi-MOF-74 for the higher alcohols synthesis from syngas

Selective conversion of syngas (CO/H2) to higher alcohols (C2+OH) is of great interest but presents a significant challenge in keeping an appropriate balance between the carbon chain growth and CO insertion to achieve a high C2+OH selectivity. Herein we found that a core-shell Co/MnOx@quasi-MOF-74 catalyst can be easily constructed through controlled deligandation of a bimetallic CoMn-MOF-74 by partial pyrolysis strategy. The as-obtained Co/MnOx@quasi-MOF-74 catalyst produces three types of synergistic active sites (Co°, coordinatively unsaturated sites (CUSs) of Co2+ and Co2C) that collaborate with each other to enhance C2+OH formation during the reaction. The Co° nanoparticles within the framework of quasi-MOF-74 enable CO dissociation and significant CHx-CHy coupling to occur while the uniformly distributed CUSs of Co2+ working with Co2C strengthen CO insertion process, leading an outstanding catalytic performance in the process of CO hydrogenation. The total selectivity of alcohols (ROH) reached 48.7 wt%, where of 93.2 wt% can be C2+OH, and very low CH4 and indetectable CO2 were produced at 200 °C, 3.0 MPa (CO/H2 = 1/2) and a gaseous hourly space velocity (GHSV) of 4500 mL g−1 h−1, reaching the catalytic performance comparable to that of the optimal level of multifunctional catalyst operated at much higher pressure (6.0 MPa). This work highlights the potential of using MOF-derived quasi-MOF materials as a tunable platform to explore highly efficient catalysts for syngas conversion.

Nanoporous materials derived from metal-organic framework for supercapacitor application

Abstract Metal-organic frameworks as a novel class of porous coordination polymers are favored in the field of supercapacitors due to their adjustable composition, high devisable structures, super-large surface area, and governable porosity. However, the low electrical conductivity and poor cycling stability restrict the utilization of MOFs as electrode material. Recently, a serious of MOF-derived nanoporous material has been applied for supercapacitor, including mono-, binary- and ternary- metal and metal matric carbon composites. In this review, the recent achievement of MOF-derived nanoporous material and their synthetic method, morphology, electrochemical performance has been discussed. The effective strategies for MOF-derived material have also been proposed, and the application and development trend have been viewed.