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Metal-organic frameworks (MOFs), or porous coordination polymers, are crystalline porous materials formed by coordination bonding between inorganic and organic species on the basis of the self-assembly of the reacting units. The typical characteristics of MOFs, including their large specific surface areas, ultrahigh porosities and excellent thermal and chemical stabilities, as well as their great potential for chemical and structural modifications, make them excellent candidates for versatile applications. Their poor electrical conductivity, however, has meant that they have not been useful for electrochemical applications. Fortuitously, the direct carbonization of MOFs results in a rearrangement of the carbon atoms of the organic units into a network of carbon atoms, which means that the products have useful levels of conductivity. The direct carbonization of zeolitic imidazolate framework (ZIF)-type MOFs, particularly ZIF-8, has successfully widened the scope of possible applications of MOFs to include electrochemical reactions that could be used in, for example, energy storage, energy conversion, electrochemical biosensors and capacitive deionization of saline water. Here, we present the first detailed protocols for synthesizing high-quality ZIF-8 and its modified forms of hollow ZIF-8, core-shell ZIF-8@ZIF-67 and ZIF-8@mesostuctured polydopamine. Typically, ZIF-8 synthesis takes 27 h to complete, and subsequent nanoarchitecturing procedures leading to hollow ZIF-8, ZIF-8@ZIF-67 and ZIF-8@mPDA take 6, 14 and 30 h, respectively. The direct-carbonization procedure takes 12 h. The resulting nanoporous carbons are suitable for electrochemical applications, in particular as materials for supercapacitors., (© 2022. Springer Nature Limited.)

Human health is being threatened by the ever-increasing water pollution. Sulfate radical (SO 4 •- , metal-organic frameworks (MOFs) are the most promising heterogeneous catalytic material in SR-AOPs because of their various structure possibilities, large surface area, ordered porous structure, and regular activation sites. Herein, an in-depth overview of MOFs and their derivatives for water purification with SR-AOPs is provided. The latest studies on pristine MOFs, MOF composites, and MOF derivatives (metal oxides, metal-carbon hybrids, and carbon materials) are summarized. The mechanisms of decomposition of pollutants in water via radical and non-radical pathways are also discussed. This review suggests future research directions for water purification through MOF-based SR-AOP.4 •- , metal-organic frameworks (MOFs) are the most promising heterogeneous catalytic material in SR-AOPs because of their various structure possibilities, large surface area, ordered porous structure, and regular activation sites. Herein, an in-depth overview of MOFs and their derivatives for water purification with SR-AOPs is provided. The latest studies on pristine MOFs, MOF composites, and MOF derivatives (metal oxides, metal-carbon hybrids, and carbon materials) are summarized. The mechanisms of decomposition of pollutants in water via radical and non-radical pathways are also discussed. This review suggests future research directions for water purification through MOF-based SR-AOP., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Sulfate radical (SO 4 )-based advanced oxidation processes (SR-AOPs) have recently attracted much attention due to their potential in degrading organic pollutants. Metal-organic frameworks (MOFs) have been reported as effective materials to generate SO •- )-based advanced oxidation processes (SR-AOPs) have recently attracted much attention due to their potential in degrading organic pollutants. Metal-organic frameworks (MOFs) have been reported as effective materials to generate SO 4 •- . However, it is challenging to separate and recover the dispersed MOF particles from the reaction solution when MOFs are used alone. We used cellulose nanofibers (CNFs) as a porous filter template to immobilize Zn-based MOF, zeolitic imidazolate framework-8 (ZIF-8), and obtained a catalytic composite membrane having peroxymonosulfate (PMS) activating function to produce SO 4 •- . The CNF was effective in holding ZIF-8 nanoparticle and making a durable porous filter. The activated PMS-produced • OH and SO 4 •- radicals from ZIF-8 play an important role in the catalytic reaction. More than 90% of methylene blue and rhodamine B was degraded by ZIF-8/CNFs composite membrane in the PMS environment within 60 min. The ZIF-8/CNFs catalytic filters can be used several times without performance reduction for organic dye degradation. The results show that ZIF-8/CNFs catalytic membrane can be separated from organic pollution system quickly and used for the efficient separation and recovery of MOF particle-based catalytic materials. Therefore, this study provides a new perspective for fabricating the MOFs particles-immobilized catalytic filter by biomass nanocellulose-based materials for water purification. This method can be used for facile fabrication of the cellulose-based porous functional filter and open diverse applications., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Numerous attempts have been made to replace commercial bulky gas chromatography (GC) systems with compact GC systems for monitoring volatile organic compounds in indoor air. However, recently developed compact GC systems are still too bulky in terms of user convenience, portability, and on-site analysis. Hence, an advanced miniaturization of compact GC systems is needed. Importantly, the small and high-performance gas pretreatment chip devices should be developed for compact GC systems. This paper reports the development of a metal–organic framework (MOF)-coated hybrid micro gas chromatography column chip (hybrid GC chip) capable of preconcentration and separation on harmful volatile organic compounds at low-concentration in one single chip device. The hybrid GC chip, 2 cm × 2 cm in size, was fabricated using a microelectromechanical systems process. The synthesized MOF-5 particles were coated on the inner wall of the fabricated hybrid GC chip and acted as an adsorbent and a stationary phase. The developed hybrid GC chip afforded high preconcentration factors with 1033–1237 and high separation resolutions with 3.8–13.3. The developed column showed good performance as a gas preconcentrator and separation column, and is the first device to perform both roles in one single chip device. [ABSTRACT FROM AUTHOR]

Porous carbon materials are suitable as highly efficient adsorbents for the treatment of organic pollutants in wastewater. In this study, we developed multiscale porous and heteroatom (O, N)-doped activated carbon aerogels (CAs) based on mesoporous zeolitic imidazolate framework-8 (ZIF-8) nanocrystals and wood using 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) oxidation, in situ synthesis, and carbonization/activation. The surface carboxyl groups in a TEMPO-oxidized wood (TW) can provide considerably large nucleation sites for ZIF-8. Consequently, ZIF-8, with excellent porosity, was successfully loaded into the TW via in situ growth to enhance the specific surface area and enable heteroatom doping. Thereafter, the ZIF-8-loaded TW was subjected to a direct carbonization/activation process, and the obtained activated CA, denoted as ZIF-8/TW-CA, exhibited a highly interconnected porous structure containing multiscale (micro, meso, and macro) pores. Additionally, the resultant ZIF-8/TW-CA exhibited a low density, high specific surface area, and excellent organic dye adsorption capacity of 56.0 mg cm−3, 785.8 m2 g−1, and 169.4 mg g−1, respectively. Given its sustainable, scalable, and low-cost wood platform, the proposed high-performance CA is expected to enable the substantial expansion of strategies for environmental protection, energy storage, and catalysis. [ABSTRACT FROM AUTHOR]

Yttria-stabilized zirconia (YSZ) nanospheres were synthesized by calcination at 900 °C after the adsorption of Y3+ ions into the pores of a zirconium-based metal–organic framework (MOF). The synthesized 3YSZ (zirconia doped with 3 mol% Y2O3), 8YSZ (8 mol% Y2O3), and 30YSZ (30 mol% Y2O3) nanospheres were found to exhibit uniform sizes and shapes. Complex permittivity and complex permeability were carried out in K-band (i.e., 18–26.5 GHz) to determine their suitability for use as low-k materials in 5G communications. The real and imaginary parts of the permittivity of the sintered 3YSZ were determined to be 21.24 and 0.12, respectively, while those of 8YSZ were 22.80 and 0.16, and those of 30YSZ were 7.16 and 0.38. Control of the real part of the permittivity in the sintered YSZ was facilitated by modifying the Y2O3 content, thereby rendering this material an electronic ceramic with potential for use in high-frequency 5G communications due to its excellent mechanical properties, high chemical resistance, and good thermal stability. In particular, it could be employed as an exterior material for electronic communication products requiring the minimization of information loss. [ABSTRACT FROM AUTHOR]

Carbon aerogels (CAs) with 3D interconnected networks hold promise for application in areas such as pollutant treatment, energy storage, and electrocatalysis. In spite of this, it remains challenging to synthesize high‐performance CAs on a large scale in a simple and sustainable manner. We report an eco‐friendly method for the scalable synthesis of ultralight and superporous CAs by using cheap and widely available agarose (AG) biomass as the carbon precursor. Zeolitic imidazolate framework‐8 (ZIF‐8) with high porosity is introduced into the AG aerogels to increase the specific surface area and enable heteroatom doping. After pyrolysis under inert atmosphere, the ZIF‐8/AG‐derived nitrogen‐doped CAs show a highly interconnected porous mazelike structure with a low density of 24 mg cm−3, a high specific surface area of 516 m2 g−1, and a large pore volume of 0.58 cm−3 g−1. The resulting CAs exhibit significant potential for application in the adsorption of organic pollutants. [ABSTRACT FROM AUTHOR]

Metal–organic framework (MOF)‐derived nanoporous carbon materials have attracted significant interest due to their advantages of controllable porosity, good thermal/chemical stability, high electrical conductivity, catalytic activity, easy modification with other elements and materials, etc. Thus, MOF‐derived carbons have been used in numerous applications, such as environmental remediations, energy storage systems (i.e. batteries, supercapacitors), and catalysts. To date, many strategies have been developed to enhance the properties and performance of MOF‐derived carbons. Herein, we introduce and summarize recent important approaches for advanced MOF‐derived carbon structures with a focus on precursor control, heteroatom doping, shape/orientation control, and hybridization with other functional materials. [ABSTRACT FROM AUTHOR]

Graphene‐organic frameworks (GOFs) is a new class of graphene‐based materials in which structure and properties can be designed by controlling the length and concentration of organic ligands, comparable to their tunable metal‐organic frameworks (MOFs) counterpart. The structural properties (e.g., surface area, pore volume) and physico‐chemical properties (e.g., electronic, thermal, and mechanical) of GOFs can be tuned based on the synthetic conditions. Such GOFs are promising as the next generation of novel materials for a wide range of potential applications such as H2 storage, electronic devices, sensors, drug carriers, etc. Here we report a review summarizing synthetic strategies, properties, and applications of GOFs. Porous framework: A review summarizing synthetic strategies, properties, and applications of graphene‐organic frameworks (GOFs), which is a new class of graphene‐based materials. [ABSTRACT FROM AUTHOR]

Carbon nanotubes (CNT) grown on nanoporous carbon (NPC), which yields coexisting amorphous and graphitic nanoarchitectures, have been prepared on a large scale from zeolitic imidazolate framework (ZIF) by introducing bimetallic ions (Co2+ and Zn2+). Interestingly, the hybrid Co/Zn-ZIF-derived NPC showed rich graphitic CNTs on the surface. This NPC was utilized for a coin-type supercapacitor cell with an aqueous electrolyte, which showed enhanced retention at high current density and good stability over 10 000 cycles. [ABSTRACT FROM AUTHOR]

Metal-organic frameworks (MOFs) are a versatile source of carbon nanoarchitectures in gas sensing applications (Torad et al., 2019). Herein, several types of nanoporous carbons (NPCs) have been prepared by in-situ carbothermal treatment of zeolitic imidazolate frameworks (ZIFs) under different inert atmospheres to achieve a highly sensitive discrimination of vaporized aromatic compounds. In this study, we demonstrate how different carbonization conditions under the flow of N 2 or H 2 gases affect the surface area and the degree of graphitization of the resulting NPCs polyhedrons, and their consequent effect on the sensing performance in terms of sensitivity and selectivity toward toxic volatile hydrocarbons. A growth of carbon nanotubes (CNTs) is observed on the surface of polyhedral NPCs after careful carbonization of ZIF crystals under H 2 atmosphere. The fabricated quartz crystal microbalance (QCM) sensor with CNT-containing NPCs demonstrates increased sensitivity and selectivity towards toxic volatile aromatic hydrocarbons over the aliphatic analogues, suggesting the rich growth of hairy graphitic-like CNTs on the surface of carbon framework act as highly selective sensing antennae for vapor molecular discrimination of toxic aromatic hydrocarbons. Despite of increased selectivity towards volatile aromatic compounds, however, the surface area of CNT-rich NPCs derived from hybrid ZIFs and ZIF-67 is greatly sacrificed as compared to CNT-free NPCs from ZIF-8 polyhedron. In the case of Co-containing ZIF-67, the rich growth of hair-like CNTs, which is induced by the presence of Co, is observed during carbothermal reduction under a flow of H 2 gas, thus allowing ultra-selective detection of aromatic hydrocarbons in the vapor phase, such as benzene (C 6 H 6) and toluene (C 6 H 5 CH 3) over their aliphatic analogue, c -hexane (c -C 6 H 12) of same molecular mass, size and vapor pressure. ga1 • A large-scale synthesis of CNTs on carbon is derived from MOF carbonized in H 2 gas. • The high content of Co species in ZIF-67 induces a rich growth hairy-like CNTs. • The QCM sensor shows an excellent sensing activity in chemical-vapor discrimination. • The rich growth CNTs act as sensing antennas selective for aromatic vapors. [ABSTRACT FROM AUTHOR]

• Nitrogen-incorporated nanoporous carbon polyhedron is derived from MOF. • Hierarchically open-porous structure is constructed for capacitive deionization. • MOF derived carbons exhibits a high capacity of 24.4 mg/g in saline water. • Carbon polyhedron shows enhanced salt adsorption rate performance. Capacitive deionization (CDI) is considered as a simple, robust, and environmentally favorable technology for water treatment. High performance electrode materials beyond commercial activated carbons (AC) should be developed for the practical application of CDI. Herein, we demonstrate hierarchically open-porous nitrogen-incorporated activated nanoporous carbon polyhedron (A-NCP) derived from metal-organic frameworks (MOFs) for high performance CDI electrodes. Owing to the 3D morphology with open nanoporous surface, macroporous channels by interlinked polyhedron particles, and electric conductivity by doped nitrogen, A-NCP delivers a high desalination capacity of 24.4 mg/g with a low concentration of 100 mg/mL at 1.2 V, revealing faster kinetic performance than that of commercial AC in the batch-mode CDI. Varying operating conditions such as applied voltage, concentration, and feed rate of saline water in a single-pass experiment, high salt adsorption capacity and fast ion removal of A-NCP are obtained, achieving high position of CDI Ragone plot. [ABSTRACT FROM AUTHOR]

The hybrid metal-organic frameworks (MOFs) with different Zn2+/Co2+ ratios are synthesized at room temperature with deionized water as the solvent. This use of deionized water can increase the yield of hybrid MOFs (up to 65–70%). After the pyrolysis, the obtained nanoporous carbons (NPCs) show a decrease in the surface area, in which the highest surface area is 655 m2 g−1. The as-prepared NPCs are subjected to activation with KOH in order to increase their surface area and convert cobalt nanoparticles (Co NPs) to Co oxides. These activated carbons are applied to electrical double-layer capacitors (EDLCs) and pseudocapacitors due to the presence of CoO and Co3O4 nanoparticles in the carbon framework, leading to significantly enhanced specific capacitance as compared to that of pristine NPCs. This synthetic method can be utilized in future research to enhance pseudocapacitance further while maintaining the maximum surface area of the carbon materials. [ABSTRACT FROM AUTHOR]

The formation of biofunctionalized metal–organic frameworks (MOFs) by growing them on a variety of macromolecular biological species, particularly on enzymes and living cells, offers exciting opportunities for a wide range of applications, including biocatalysis, biosensing, and diagnoses. MOFs are commonly subjected to biofunctionalization and biomimetic mineralization, owing to their good chemical and thermal stabilities and easy preparation in aqueous medium under ambient conditions. The functionalization of MOFs with biological substances, such as enzymes, nonenzymatic proteins, and living cells promotes the formation of MOF‐based biocomposites which retain the biological functions of the embedded biological substances. The most common method to construct these biofunctionalized MOFs is either by directly growing the MOF on the biological moiety or by postsynthetic modification of the exterior surface of the MOF with the desired biological species. In particular, hierarchically porous MOFs (containing both mesopores and micropores) are ideal candidates for hosting enzymes and for the translocation of nonenzymatic proteins. This review covers various advanced strategies for developing MOF‐based biocomposites for a wide range of bioapplications, such as biomedical storage, tumor cell targeting, and drug delivery. The influence of MOFs on the biological activity of living cells and future prospects for developing novel MOF‐based biorefinery are discussed. [ABSTRACT FROM AUTHOR]

The pollution of the environment by volatile organic compounds (VOCs) and the resulting threat on human health are increasing, and this has prompted the development of advanced functional materials for the removal of VOCs. Metal-organic frameworks (MOFs) possess numerous desirable properties, such as controllable topological structures, adaptable porosity, high surface area, and exceptional chemical-thermal stability, which make them attractive candidates for VOCs removal. However, the easy aggregation and inherent crystal structure of MOFs severely limit their performance and corresponding applications. The synthesis of MOFs-based composites with structurally-manipulable MOFs nanocrystals as a substrate is considered to be an important step in the industrial application of MOFs for the removal of VOCs. Particularly, compounding MOFs into green-renewable cellulose through relevant strategies to fabricate nanocellulose–MOFs composites (CelloMOFs) is expected to solve the application limitation of MOFs caused by their defect. Herein, the research progress on CelloMOFs, in terms of their synthesis strategies, prevalent forms, and methods of VOCs removal, is comprehensively reviewed. Furthermore, the potential mechanism involved in the elimination of VOCs by CelloMOFs is comprehensively presented, including the range of factors influencing the adsorption capacity of CelloMOFs. In addition, the catalytic and membrane separation strategies of CelloMOFs for the removal of VOCs are reviewed. Furthermore, the limitations and potential research directions of CelloMOFs for VOCs removal are discussed. The unique properties of CelloMOFs will open up new avenues for their extensive application for VOCs remediation. • The in-situ synthesis and ex-situ blending methods for fabricating CelloMOFs composites were introduced. • The varied forms of CelloMOFs composites for VOCs removal were discussed. • The mechanisms of CelloMOFs for the removal of VOCs were summarized. • The CelloMOFs composits' limitations and possible future research directions in the field of VOCs removal were prospected. [ABSTRACT FROM AUTHOR]

[Display omitted] • Photocatalytic MOF filter (PMF) was prepared with MOF by EPD method. • MOF-based PMF showed good adsorption/removal performance for VOCs. • The removal efficiency was found as 94.25% for VOCs. • PMF exhibited a good durability after 50 repetitions. • PMF can be applied to various photocatalytic materials for air purification systems. Adsorption/removal of volatile organic compounds (VOCs) has become essential for indoor air quality management because of their harmful effect on the human body. In this study, we report on an indoor VOC filter system using a photocatalytic metalorganic framework (MOF) filter (PMF) based on MIL-100(Fe) with a particle size of ∼ 160 nm. The PMF was prepared by the electrophoretic deposition of MOF nanoparticles on a porous nickel foam. The MOF nanoparticles were uniformly coated on a large-sized conductive Nickel foam (up to a 10 cm diameter) without uncoated metal foam. To evaluate the adsorption/removal performance of VOCs on the developed PMF, a testbed system, including a photoionization detector, a carbon dioxide sensor, an ultraviolet (UV) light-emitting diode module, and a fan module, was developed, and a filter system was set up. The fabricated PMF showed excellent adsorption and decomposition of the adsorbed VOCs under UV light due to the high specific surface area and photocatalytic property of MIL-100(Fe). The average adsorption and removal performances of the PMF for 10 experiments were 94.25% and 75.95%, respectively. In the durability test, the PMF indicated 72.65% removal efficiency after conducting recycling tests 50 times, and the structure of the PMF was stable. Our approach provides an easy method for preparing MOF-based photocatalytic filters for use in an indoor VOC purification system. We believe that the prepared PMF has good stability and durability for VOC removal and can be applied to various applications such as home, automobile, office, and industry. [ABSTRACT FROM AUTHOR]

• Synthesis strategies of enzyme-MOFs are discussed in detail. • The applications of enzyme-MOFs for water treatment are summarized. • The future perspectives and challenges of enzyme-MOFs for water treatment are discussed. The rapid development of the world economy and industrialization has brought about the increase of contaminants in water, which makes the removal and detection of contaminants high priority. Enzyme-based water treatment technology is an efficient and economical method, but its industrial application faces great challenges. The encounter between enzyme and metal–organic frameworks (MOFs) offers a glimmer of hope for solving the above problems, benefiting from the fascinating advantages of MOFs. This review discusses the synthesis strategies of enzyme-MOFs for water treatment and highlights the applications of enzyme-MOFs in water treatment, including removal of emerging contaminants and as an emerging sensing platform for contaminants. Furthermore, the conclusions and future perspectives are discussed and delineated. The objective of this review is to provide a new perspective on the emerging enzyme-MOFs-based platform for innovative employment in water treatment and to accelerate the development of this field for early industrial application. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel metal-free carbonaceous membrane was fabricated with ZIF-8@CNFs membrane by pyrolysis process. • NCNFs/PMS system demonstrated a remarkable catalytic efficiency for MB removal. • NCNFs membrane remained superior reusability and stability in 5 times recycling by annealing process. • Non-radical pathways are dominant in MB degradation with the NCNFs/PMS system. • NCNFs membrane has a promising serve as a filter in practical organic dye remediation application. N -doped carbon materials have been considered as promising efficient and environment-friendly catalysts for sulfate radical-based advanced oxidation processes (SR-AOPs). Herein, we first report a facile strategy to prepare nanoporous N -doped carbon nanofilters (NCNFs) using cellulose nanofibers (CNFs) and metal–organic framework (MOF) as the superior metal-free catalytic for SR-AOPs. In this work, CNFs are employed as nanoporous templates and binders to fix ZIF-8 for fabricating ZIF-8@CNF membrane, and the as-prepared membrane was converted into NCNFs by a simple pyrolysis process. To evaluate the catalytic degradation performance of the NCNFs, methylene blue (MB) was chosen as a model contaminant. It is found that the NCNFs demonstrate a remarkable efficiency for MB removal by peroxymonosulfate (PMS) activation, and 96 % of MB (10 mg/L) was degraded in 15 min. The catalytic reaction and process including removal and washing are very simple and easy because the nanoporous N -doped carbons are fixed on CNF-derived networks. Furthermore, the reaction parameters including reaction temperature, pH, and catalyst/PMS dosage are also investigated. In addition, a series of radical quenching experiments reveal that non-radical mechanism is responsible for the degradation of MB. Importantly, the NCNFs membrane showed a good reusability by the annealing process and it can serve as a catalytic filter in practical organic dye remediation application. This present work shows that MOF derived metal-free carbon membranes have a promising avenue as catalysts for organic dye degradation and water remediation. [ABSTRACT FROM AUTHOR]