MOF-derived Porous Carbon Research Articles

Tailoring MOF-derived porous carbon nanorods confined red phosphorous for superior potassium-ion storage

Abstract The metal-organic framework Zn-MOF-74, which has abundant oxygen-containing groups and Zn elements as pore creators during pyrolysis, can be an ideal precursor for a porous carbon matrix in battery electrodes, but its irregular morphology at the micron size is unfavorable. Here we demonstrate the facile solvothermal synthesis of uniform Zn-MOF-74 hexagonal nano/microrods (ZRods) with an accurate diameter modulation from tens of nanometers to micron size through varying the H2O content in the mixed solvent. An inverted volcano relationship between the ZRod diameters and H2O contents is presented. CH3COO- is identified to be critical to the hexagonal pillar shape formation, while a competitive reaction of protons dissociated from H2O is responsible for the size modulation. After calcination, the obtained porous carbon nanorods enable a high loading capacity and perfect encapsulation of P while reserving free spaces to accommodate the volume change of P in the composite anode, resulting in outstanding potassium storage performance in terms of remarkable initial Coulombic efficiency (78.5%), top-ranking reversible capacity (up to 595.8 mAh g-1), superior rate capability (187.5 mAh g-1 at 5 A g-1), and robust long-term cycling stability (retaining 150.7 mAh g-1 at 2.5 A g-1 after 400 cycles). This morphology modulation of Zn-MOF-74 will promote the advanced applications of Zn-MOF-74 as well as its derived carbon materials, and potentially opens a general pathway for the oriented evolution of various carboxylate-based MOFs.

Synergistic carbon coating of MOF-derived porous carbon and CNTs on silicon for high performance lithium-ion batteries

Silicon has been considered as one of the most potential alternatives to traditional graphite anode materials in lithium-ion batteries (LIBs) due to its high specific capacity. However, the practical application of silicon is hampered by its inherent low conductivity and huge volumetric expansion during cycling. Herein, a hybrid of [email protected] nanotubes (CNTs)@carbon nanocomposites in which Si nanoparticles tangled with CNTs are encapsulated into metal-organic-frameworks (MOFs) carbon shell was synthesized through chemical vapor deposition and MOF self-template methods. By growing CNTs on the surface of Si nanoparticles, it is possible to facilitate their encapsulation in ZIF-67 crystals. In addition, the synergistic effect between CNTs and carbon shells doped with nitrogen can efficaciously buffer the expansion of structure and enhance the conductivity of materials. Besides, the porosity of carbon shell and the connection of CNTs can provide channels for the penetration and diffusion of Li+. On the basis of the above merits, the reversible capacity of the resulted composite remains 568.8 mAh g−1 after 200 cycles at 1 A g−1. Moreover, it exhibits a preferable rate performance, thus indicating that this composite is a promising anode material for LIBs.

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.

Recent progress of MOF-derived porous carbon materials for microwave absorption.

Microwave absorbing materials (MAM) have attracted considerable attention over the years in stealth and information technologies. Metal–organic framework (MOF) with a unique microstructure and electronic state has become an attractive focus as self-sacrificing precursors of microwave absorbers. The MOF-derived porous carbon (PC) materials exhibit a high absorbing performance due to the stable three-dimensional structure and homogeneous distribution of metal particles. MOF-derived PC materials are promising for ideal MAM via tuning of the structure and composition, resulting in appropriate impedance matching and the synergistic effect between magnetic and dielectric loss. In this review, the MOF-derived PC materials and their basic absorption mechanisms (dielectric loss, magnetic loss and impedance matching) are introduced, as well as the characters of various MOF-derived PC materials. In addition, this review provides a comprehensive introduction and tabulates the recent progress based on the classification of the MOF-derived metallic state, such as pure PC (without reduced metals), mono-metal/PC, multi-metal/PC, metal oxides/PC and other derived PC composites. Finally, the challenges faced by MOF-derived PC materials are overviewed, and their further development is mentioned.

Highly dispersed secondary building unit-stabilized binary metal center on a hierarchical porous carbon matrix for enhanced oxygen evolution reaction.

Restricting the aggregation and rationally adjusting the electronic structure of binary metal centers in metal-organic framework (MOF) precursors are important for optimizing their performance as electrocatalysts for the oxygen evolution reaction (OER) and achieving low overpotential and high stability in such applications. Herein, we demonstrate the possibility of enhancing the electrochemical activity of MOF-derived binary metal center catalysts by controlling the form of the Fe species. The introduction of Fe-SBU (iron 2,5-dihydroxyterephthalic acid) into ZIF-67 is found to induce a distinct confinement effect and this can be exploited to improve the electroconductivity of binary metal center catalysts, and therefore, to reduce the OER reaction barrier (OOH* → O*). When applied as an OER catalyst in 1 M KOH solution, the Fe-SBU@Co-Matrix catalyst exhibits a low overpotential of 249 mV to reach a current density of 10 mA cm-2 and high stability for over 40 h. This work describes the secondary growth treatment of MOF-derived porous carbons to promote their application as catalysts in energy conversion reactions.

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-derived porous carbon inlaid with MnO2 nanoparticles as stable aqueous Zn-ion battery cathodes.

Cathodes derived from metal-organic framework materials offer unique advantages in terms of improved structural reversibility and electron conduction efficiency. Nevertheless, the capacity contribution of cathodes based on the carbon framework system has not been clearly discussed or is controversial in aqueous batteries. In this essay, we have uncovered the capacity contribution arising from the adsorption of anions/cations onto the carbon surface by examining the bonds of the carbon and the details of unsteady voltage in the CV/GITT during the discharge. Benefiting from the synergistic contribution of the double-layer capacitance and pseudocapacitance, Zn/C-MnO2 exhibits excellent long-cycling stability and fast kinetics. To the best of our knowledge, this is the first report on the ion adsorption-based double layer effect in aqueous zinc ion batteries. Such a capacity contribution mechanism, and a renewed knowledge of the discharge mechanism, will contribute to the development of high-performance aqueous zinc ion batteries.

Porous Carbon-Based Supercapacitors Directly Derived from Metal-Organic Frameworks.

Numerously different porous carbons have been prepared and used in a wide range of practical applications. Porous carbons are also ideal electrode materials for efficient energy storage devices due to their large surface areas, capacious pore spaces, and superior chemical stability compared to other porous materials. Not only the electrical double-layer capacitance (EDLC)-based charge storage but also the pseudocapacitance driven by various dopants in the carbon matrix plays a significant role in enhancing the electrochemical supercapacitive performance of porous carbons. Since the electrochemical capacitive activities are primarily based on EDLC and further enhanced by pseudocapacitance, high-surface carbons are desirable for these applications. The porosity of carbons plays a crucial role in enhancing the performance as well. We have recently witnessed that metal–organic frameworks (MOFs) could be very effective self-sacrificing templates, or precursors, for new high-surface carbons for supercapacitors, or ultracapacitors. Many MOFs can be self-sacrificing precursors for carbonaceous porous materials in a simple yet effective direct carbonization to produce porous carbons. The constituent metal ions can be either completely removed during the carbonization or transformed into valuable redox-active centers for additional faradaic reactions to enhance the electrochemical performance of carbon electrodes. Some heteroatoms of the bridging ligands and solvate molecules can be easily incorporated into carbon matrices to generate heteroatom-doped carbons with pseudocapacitive behavior and good surface wettability. We categorized these MOF-derived porous carbons into three main types: (i) pure and heteroatom-doped carbons, (ii) metallic nanoparticle-containing carbons, and (iii) carbon-based composites with other carbon-based materials or redox-active metal species. Based on these cases summarized in this review, new MOF-derived porous carbons with much enhanced capacitive performance and stability will be envisioned.

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.

PtRu bimetallic nanoparticles embedded in MOF-derived porous carbons for efficiently electrochemical sensing of uranium

PtRu bimetallic nanoparticles embedded in MOF-derived porous carbons (PtRu-PCs) were synthesized by first loading PtRu bimetallic nanoparticles into a UiO66-NH2 host matrix and then going in situ carbonization at high temperatures. In the synthetic strategy, UiO66-NH2 was used not only as a precursor to limit the aggregation and migration of PtRu bimetallic nanoparticles, but also as a self-sacrificial template to improve the conductivity. The as-prepared PtRu-PCs were characterized by SEM, TEM, XRD, and XPS. The PtRu-PC-based sensor had excellent sensitivity with a detection limit of 0.024 μM (S/N = 3). The developed method was successfully applied to real water samples with a recovery rate of 92–107%.

Carbonated MOF-based graphene hydrogel for hierarchical all‑carbon supercapacitors with ultra-high areal and volumetric energy density

Abstract Graphene hydrogel (GH) has been widely explored as electrode material for supercapacitors due to its three-dimensional porous network structure. However, poor conductivity and low capacitance activity have limited practical application. Herein, we design and fabricate a hierarchical all‑carbon GH-based electrode material decorated with MOF-derived porous carbon (cZIF-8) and highly N-doped graphene quantum dots. In this N-GQD@cZIF-8/GH composite, GH constructs an interconnected porous structure which benefits rapid electron/ion transport, and cZIF-8 provides a large specific surface area and enhances electrical conductivity, while N-GQDs contribute pseudo-capacitance and improve the wettability. The supercapacitor based on N-GQD@cZIF-8/GH shows a high areal capacitance (617.1 mF cm−2) and areal energy density (85.7 μWh cm−2) at 1 mA cm−2. It also has good rate capability (81.5% at 20 mA cm−2) and excellent cycling stability (93.1% after 10,000 cycles). Moreover, the assembled all-solid-state flexible supercapacitor can deliver a high energy density of 18.1 mWh cm−3 at high power density of 4907.3 mW cm−3. This rational-designed all‑carbon electrode opens up opportunities in the fabrication of next-generation wearable electronic equipments.

Boosting storage properties of reduced graphene oxide fiber modified with MOFs-derived porous carbon through a wet-spinning fiber strategy

Supercapacitors that are light weight and flexible, while occupying a low volume and demonstrating good mechanical properties are in demand for portable energy storage devices. Graphene composite fibers are supposed to be ideal electrodes for flexible fiber-shaped supercapacitors. Integration of MOFs-derived porous carbon into graphene fibers provides desirable electrochemical and mechanical properties. Herein, a general strategy is shown for the preparation of MOFs-derived porous carbon/reduced graphene oxide fibers. Close-packed and aligned graphene sheets along with porous MOFs-derived porous carbon can achieve outstanding mechanical properties through synergistic effects. Consequently, a large specific capacitance of 56.05 F cm−3, a good tensile property of 86.5 MPa and a high retention of 96.6% after 10 000 cycles can be achieved with the composite fibers. Moreover, a further deposition of polyaniline (PANI) and manganese dioxide (MnO2) by in situ growth on the fabricated composite fibers provide an improvement in specific capacitance with value of 74.21 F cm−3 and 65.08 F cm−3, respectively. The above results demonstrate the promising application of composite fibers as a flexible and stable electrode and substrate for energy storage devices.

Conversion of Co Nanoparticles to CoS in Metal-Organic Framework-Derived Porous Carbon during Cycling Facilitates Na2S Reactivity in a Na-S Battery.

Room-temperature sodium-sulfur batteries have attracted wide interest due to their high energy density and high natural abundance. Polysulfide dissolution and irreversible Na2S conversion are challenges to achieving high battery performance. Herein, we utilize a metal-organic framework-derived Co-containing nitrogen-doped porous carbon (CoNC) as a catalytic sulfur cathode host. A concentrated sodium electrolyte based on sodium bis(fluorosulfonyl)imide, dimethoxyethane, and bis(2,2,2-trifluoroethyl) ether is used to mitigate polysulfide dissolution. We tune the amount of Co present in the CoNC carbon host by acid washing. Significant improvement in reversible sulfur conversion and capacity retention is observed with a higher Co content in CoNC, with 600 mAh g-1 and 77% capacity retention for CoNC and 261 mAh g-1 and 56% capacity retention for acid-washed CoNC at cycle 50 at 80 mAh g-1. Post-mortem X-ray photoelectron spectroscopy, transmission electron microscopy, and selected area electron diffraction suggest that CoS is formed during cycling in place of Co nanoparticles and CoN4 sites. Raman spectroscopy suggests that CoS exhibits a catalytic effect on the oxidation of Na2S. Our findings provide insights into understanding the role Co-based catalysts play in sulfur batteries.

Metal-Organic Framework@Carbon Hybrid Magnetic Material as an Efficient Adsorbent for Pollutant Extraction.

The preparation of a hybrid magnetic metal-organic framework (MOF)@carbon from a MOF-derived porous carbon is reported. MOF-74(Co) is used as a precursor for the synthesis of a magnetic carbon with homogeneous cobalt particle distribution (C-MOF-74) by a direct carbonization step. The cobalt particles present in the carbon are partially converted to zeolitic imidazolate framework (ZIF)-67 by reaction with 2-methylimidazole to obtain a core-shell ZIF-67@C-MOF-74. The effect of the reaction time and 2-methylimidazole concentration in the conversion procedure is studied by X-ray diffraction and scanning microscopy. Because of its high surface area, dual porosity, and magnetic properties, ZIF-67@C-MOF-74 exhibits high extraction capacity (180 mg g-1), fast adsorption rate, and excellent recyclability for Congo red adsorption. In addition, the prepared material shows high efficiency in the extraction of different phenolic compounds. The developed procedure can be easily adapted to different carbons and MOFs, thus potentially enabling the preparation of a wide number of new hybrid materials.

Metal-organic frameworks derived porous carbon, metal oxides and metal sulfides-based compounds for supercapacitors application

The energy storage field has witnessed a dramatic expansion in terms of short charging time of supercapacitors, especially in the highly active electrode materials. Metal-organic frameworks (MOFs) materials have been extensively applied as precursors or templates for the synthesis of carbon, metal oxides/sulfides-based compounds as high-performance electrodes in supercapacitors. The MOFs-derived materials can be broadly divided into two groups: MOFs-derived porous carbon and MOFs-derived metal oxide/sulfide compounds. These MOFs-derived materials are characterized by unique porous structures, controllable structures, high surface area, good conductivity (MOFs-derived carbon) and outstanding electrochemical stability, meeting the requirements of the desirable specific capacitance and long-term cyclic performance of both electrochemical double layer capacitors and pseudocapacitors. However, MOFs-derived materials still suffer from the complex synthesis process and high production cost of MOFs precursors, difficulties in mass production, and unstable structure in highly corrosive electrolyte. In addition, the electrical conductivity of MOFs-derived metal oxides/sulfides needs to be further improved. In this review, we summarize the recent progresses in the development of MOFs-derived porous carbons and metal oxide/sulfide compounds and their applications in supercapacitors. The prospects and challenges of MOFs-derived carbon and metal oxide/sulfide compounds as highly effective and durable electrodes in supercapacitors are discussed.

Simultaneous removal of butylparaben and arsenite by MOF-derived porous carbon coated lanthanum oxide: Combination of persulfate activation and adsorption

A novel multifunctional material of MOF-derived porous carbon coated lanthanum oxide (donated as La-MOF-900) had been successfully synthesized by hydrothermal-calcination method, which used in the simultaneous removal of butylparaben (BPB) and As(III). For the single contaminant system, the degradation rate of BPB could reach 98% and retain a high removal efficiency in a wide pH range of 3–9, which covered the most wastewater. In contrast, the removal rate of As(III) reached 90% in the pH of 3, and still 70% of the As(III) can be removed in the pH of 9. For the BPB-As(III) binary system, the presence of As(III) had no obvious impact on the degradation rate of BPB. However, the removal rate of As(III) was suppressed at the presence of BPB because of the competitive reaction of radicals between BPB and As(III). O2−, 1O2, HO and SO4− were all involved in La-MOF-900/PS system. The composition of porous carbon in the La-MOF-900 was responsible for activating persulfate to degrease BPB and oxidize As(III) to As(V) while La2O3 component of La-MOF-900 acted as adsorbent for the removal of evolved As(V). The proposed strategy would be very indicative for the efficient co-removal of combined pollutants in the aqueous solution.

Electrochemical thrombin aptasensor based on using magnetic nanoparticles and porous carbon prepared by carbonization of a zinc(II)-2-methylimidazole metal-organic framework.

A homogeneous electrochemical aptasensor was obtained by modifying a glassy carbon electrode (GCE) with a porous carbon nanomaterial (Z-1000, about 70nm, deteced by transmission electron microscopic) that was obtained by carbonization of a zinc(II)-2-methylimidazole metal-organic framework. Z-1000 possesses a large specific surface and outstanding electrochemical properties. A thrombin-binding aptamer (CP) was immobilized on the magnetite nanoparticles MNPs by the condensation reaction and further combined with reporter probe (RP) that is functionalized with electroactive methylene blue (MB). In the presence of thrombin, the CP was specifically recognized with it to formthe CP/MNP/Thb complex, and the RP was dissociated from MNPs. The released RP was captured by the modified GCE through π-stacking interaction between nucleobases and carbon nanostructure. The electrical signal generatedby MB can be monitored by differential pulse voltammetry (DPV). Under the optimized conditions, the DPV peak current at around -0.28V (vs.SCE) increases with thrombin concentration. The sensor has a detection limit of 0.8 fM of thrombin and a linear range that extends from 10 fM to 100nM. It was successfully applied to the analysis of spiked serum. The recoveries are 98.1-99.4% and RSDs are 3.9%-4.0%. Conceivably, this aptasensor schemecan be easily extended to other proteins and gives inspiration to manufacture sensitive aptasensor. Graphical abstract A homogeneous electrochemical aptasensor is obtained by modifying a glassy carbon electrode with the MOF-derived porous carbon. The sensor has a detection limit of 0.8 fM and a wide linear range from 10 fM to 100nM for thrombin detection.

Multifunctional β-Cyclodextrin MOF-Derived Porous Carbon as Efficient Herbicides Adsorbent and Potassium Fertilizer

Multifunctional material for simultaneous pollutants removal and nutrient release is a novel, economical, and sustainable strategy to reuse agricultural wastewater and improve crop growth. Herein, ...

MOF-derived porous carbon supported iron-based catalysts with optimized active sites towards oxygen reduction reaction

Development of earth-abundant materials as novel substitutes for platinum group metal catalysts towards the oxygen reduction reaction (ORR) remains a great challenge to drive the commercialization of fuel cell. Iron-based catalysts were synthesized by using a metal-organic framework (MOF) as the precursor. FeNC-650, which is obtained by pyrolyzed at 650°C, is composed of Fe and Fe3O4 nanoparticles encapsulated in the nitrogen-enriched mesoporous carbon. It exhibits higher electrocatalytic activity and stability, compared with other FeNC catalysts and commercial Pt/C for ORR. The effect of pyrolysis temperature on active sites and unique structures is investigated. The excellent electrocatalytic performance and superior stability make it a promising non-precious metal catalyst for practical fuel cell application.

Isomorphic MOF-derived porous carbon materials as electrochemical sensor for simultaneous determination of hydroquinone and catechol

It is needed to speed up the development of a sensitive detection platform for simultaneous determination of dihydroxybenzene isomers with harmful properties. Here, two isomorphic Metal–organic frameworks (MOFs) [Zn(Trz)(R-BDC)1/2] (FJU-40-R, R = H or NH2; Trz = 1,2,4-Triazole; H-BDC = terephthalic acid) were selected to derive two N-doping porous carbon (NPC) materials. Further, a strategy for constructing electrochemical sensors for simultaneous determination of hydroquinone (HQ) and catechol (CT) was proposed by the MOF-derived NPC modifying glass carbon electrode (GCE). It was found that HQ and CT had good responses on NPC-FJU-40-H/GCE, but had no obvious responses on NPC-FJU-40-NH2/GCE. NPC-FJU-40-H/GCE displayed excellent reproducibility, stability, and anti-interference. Under the optimal conditions, the linear ranges of HQ and CT on NPC-FJU-40-H/GCE were 1 ~ 70 µmol L−1 and 1 ~ 100 µmol L−1 with the detection limits of 0.18 µmol L−1 for HQ and 0.31 µmol L−1 for CT, respectively. Although the porous carbon (PC) derived from MOFs has been applied in electrochemical sensing, the effect of the ligand functional groups of isomorphic MOFs on the electrochemical properties of the derived PC materials is still lack of relevant research. Our research provided an idea that the electrocatalysis properties of MOF-derived porous carbon materials could be tuned by changing the functional groups in ligands of isomorphic MOFs in electrochemical sensing field. A feasible strategy was proposed by changing the ligands of the two isomorphic MOFs (FJU-40-H and FJU-40-NH2) to tune the electrocatalysis properties of MOF-derived N-doped porous carbon materials for the simultaneous determination of dihydroxybenzene isomer.