Covalent‐Organic Frameworks (COFs) as Proton Conductors

Advanced Energy Materials, Journal Year: 2021, Volume and Issue: 11(39)

Published: Sept. 1, 2021

Abstract Proton conductivity is the paramount property of proton‐conducting materials that are playing significant roles in diverse electrochemical devices with applications proton exchange membranes (PEMs) for fuel cells (PEMFCs). Considering scarcity fossil fuels, development clean and green renewable energy resources in‐demand across globe. Toward this direction, solid‐state conductors interest. The higher structural tunability, lower density, good crystallinity, accessible well‐defined pores, excellent thermal chemical stability covalent‐organic frameworks (COFs) make them versatile platforms as both under hydrous anhydrous conditions. Taking advantage such superior properties, reports on COFs have been increasing swiftly since 2014, which demands a summarization comprehensive discussion “at glance” visualization further development. In review, showcased newer class material. A presented by organizing strategies taken to develop COFs. Establishment structure–function relationships implementation discussed well. Moreover, challenges future prospects elaborately critically analyzed.

Language: Английский

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Porous organic polymers for high-performance supercapacitors

Chemical Society Reviews, Journal Year: 2022, Volume and Issue: 51(8), P. 3181 - 3225

Published: Jan. 1, 2022

This review summarizes recent advances and design strategies of porous organic polymers as efficient electrode materials for high-performance supercapacitors.

Language: Английский

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Grotthuss Proton‐Conductive Covalent Organic Frameworks for Efficient Proton Pseudocapacitors

Angewandte Chemie International Edition, Journal Year: 2021, Volume and Issue: 60(40), P. 21838 - 21845

Published: Aug. 9, 2021

Abstract Herein, we describe the synthesis of two highly crystalline, robust, hydrophilic covalent organic frameworks (COFs) that display intrinsic proton conduction by Grotthuss mechanism. The enriched redox‐active azo groups in COFs can undergo a proton‐coupled electron transfer reaction for energy storage, making ideal candidates pseudocapacitance electrode materials. After situ hybridization with carbon nanotubes, composite exhibited high three‐electrode specific capacitance 440 F g −1 at current density 0.5 A , among highest COF‐based supercapacitors, and retain 90 % even after 10 000 charge–discharge cycles. This is first example using proton‐conductive materials to create pseudocapacitors both power density. assembled asymmetric two‐electrode supercapacitor showed maximum 71 Wh kg 42 kW surpassing all reported systems.

Language: Английский

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Immobilized covalent triazine frameworks films as effective photocatalysts for hydrogen evolution reaction

Nature Communications, Journal Year: 2021, Volume and Issue: 12(1)

Published: Nov. 15, 2021

Covalent triazine frameworks have recently been demonstrated as promising materials for photocatalytic water splitting and are usually used in the form of suspended powder. From a practical point view, immobilized CTFs more suitable large-scale splitting, owing to their convenient separation recycling potential. However, existing synthetic approaches mainly result insoluble unprocessable powders, which make future device application formidable challenge. Herein, we report an aliphatic amine-assisted interfacial polymerization method obtain free-standing, semicrystalline film with excellent photoelectric performance. The lateral size was up 250 cm2, average thickness can be tuned from 30 500 nm. structure confirmed by high-resolution transmission electron microscope, powder X-ray diffraction, grazing-incidence wide-angle scattering, small-angle scattering analysis. Intrigued good light absorption, crystalline structure, large film, on glass support exhibited hydrogen evolution performance (5.4 mmol h-1 m-2) presence co-catalysts i.e., Pt nanoparticles easy recycle.

Language: Английский

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Assembling covalent organic framework membranes with superior ion exchange capacity

Nature Communications, Journal Year: 2022, Volume and Issue: 13(1)

Published: Feb. 23, 2022

Ionic covalent organic framework membranes (iCOFMs) hold great promise in ion conduction-relevant applications because the high content and monodispersed ionic groups could afford superior conduction. The key to push upper limit of conductivity is maximize exchange capacity (IEC). Here, we explore iCOFMs with a superhigh 4.6 mmol g-1, using dual-activation interfacial polymerization strategy. Fukui function employed as descriptor monomer reactivity. We use Brønsted acid activate aldehyde monomers phase base amine water phase. After dual-activation, reaction between at water-organic interface significantly accelerated, leading crystallinity. resultant display prominent proton up 0.66 S cm-1, holding transport separation applications.

Language: Английский

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Zwitterionic Covalent Organic Frameworks: Attractive Porous Host for Gas Separation and Anhydrous Proton Conduction

ACS Nano, Journal Year: 2021, Volume and Issue: 15(12), P. 19743 - 19755

Published: Nov. 30, 2021

Ionic covalent organic frameworks (COFs) consisting of an anionic or cationic skeleton and corresponding counterions have demonstrated great potential in many application fields such as ion conduction, molecular separation, catalysis. However, arranging groups into the same COF to form zwitterionic materials is still unexplored. Herein we design synthesis three COFs attractive porous hosts for SO2/CO2 separation anhydrous proton conduction. The separated COFs' channels can act two different polar sites SO2 adsorption, allowing achieve a high adsorption capacity (216 mL/g, 298 K) impressive selectivity (118, K). Furthermore, after loading with triazole/imidazole, induce complete carrier deprotonation, producing more freely migrating protons. free protons migrate along continuous hydrogen-bonding network channels, leading outstanding conductivity up 4.38 × 10-2 S/cm, which much higher than other N-heterocyclic-doped under conditions. Proton dissociation energy calculations combined frequency-dependent dielectric analysis give insight role conductivity. Our work provides possibility well-defined gas

Language: Английский

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Fluids and Electrolytes under Confinement in Single-Digit Nanopores

Chemical Reviews, Journal Year: 2023, Volume and Issue: 123(6), P. 2737 - 2831

Published: March 10, 2023

Confined fluids and electrolyte solutions in nanopores exhibit rich surprising physics chemistry that impact the mass transport energy efficiency many important natural systems industrial applications. Existing theories often fail to predict exotic effects observed narrowest of such pores, called single-digit (SDNs), which have diameters or conduit widths less than 10 nm, only recently become accessible for experimental measurements. What SDNs reveal has been surprising, including a rapidly increasing number examples as extraordinarily fast water transport, distorted fluid-phase boundaries, strong ion-correlation quantum effects, dielectric anomalies are not larger pores. Exploiting these presents myriad opportunities both basic applied research stand host new technologies at water-energy nexus, from membranes precise separations purification gas permeable materials electrolyzers energy-storage devices. also present unique achieve ultrasensitive selective chemical sensing single-ion single-molecule limit. In this review article, we summarize progress on nanofluidics SDNs, with focus confinement arise extremely narrow nanopores. The recent development precision model systems, transformative tools, multiscale played enabling roles advancing frontier reviewed. We identify knowledge gaps our understanding nanofluidic provide an outlook future challenges frontier.

Language: Английский

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Highly Crystalline Polyimide Covalent Organic Framework as Dual-Active-Center Cathode for High-Performance Lithium-Ion Batteries

Journal of the American Chemical Society, Journal Year: 2022, Volume and Issue: 144(51), P. 23534 - 23542

Published: Dec. 13, 2022

Polyimide covalent organic framework (PI-COF) materials that can realize intrinsic redox reactions by changing the charge state of their electroactive sites are considered as emerging electrode for rechargeable devices. However, highly crystalline PI-COFs with hierarchical porosity less reported due to rapid reaction between monomers and poor reversibility polyimidization reaction. Here, we developed a water-assistant synthetic strategy adjust rate polyimidization, PI-COF (COFTPDA-PMDA) kgm topology consisting dual active centers N,N,N′,N′-tetrakis(4-aminophenyl)-1,4-benzenediamine (TPDA) pyromellitic dianhydride (PMDA) ligands was successfully synthesized high crystallinity porosity. The COFTPDA-PMDA possesses micro-/mesoporous channels largest surface area (2669 m2/g) in PI-COFs, which promote Li+ ions bulky bis(trifluoromethanesulfonyl)imide (TFSI–) electrolyte sufficiently interact on COF skeleton increase specific capacity cathode materials. As material lithium-ion batteries, COFTPDA-PMDA@50%CNT integrated center carbon nanotubes via π–π interactions gave initial 233 mAh/g (0.5 A/g) maintains at 80 even current density 5.0 A/g after 1800 cycles.

Language: Английский

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Tuning the Interlayer Interactions of 2D Covalent Organic Frameworks Enables an Ultrastable Platform for Anhydrous Proton Transport

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 61(35)

Published: July 8, 2022

The development of effective, stable anhydrous proton-conductive materials is vital but challenging. Covalent organic frameworks (COFs) are promising platforms for ion and molecule conduction owing to their pre-designable structures tailor-made functionalities. However, poor chemical stability due weak interlayer interactions intrinsic reversibility linkages. Herein, we present a strategy enhancing the two-dimensional COFs via importing planar, rigid triazine units into center C3 -symmetric monomers. developed triazine-core-based COF (denoted as TPT-COF) possesses well-defined crystalline structure, ordered nanochannels, prominent porosity. proton conductivity was ≈10 times those non-triazinyl COFs, even reaching up 1.27×10-2 S cm-1 at 160 °C. Furthermore, TPT-COF exhibited structural ultrastability, making it an effective transport platform with remarkable long-term durability.

Language: Английский

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Current Challenges and Perspectives of Polymer Electrolyte Membranes

Macromolecules, Journal Year: 2022, Volume and Issue: 55(10), P. 3773 - 3787

Published: May 4, 2022

Polymer electrolyte membranes are charged polymers in the membrane shape, which can separate anode reaction from cathode reaction, allowing fabrication of compact and highly efficient electrochemical devices. In recent years, great success has been witnessed development advanced polymer membranes, driven by fast fuel cells that promise a clean sustainable energy supply. However, drawbacks limiting widespread adoption still exist. These include high cost fluorinated poor ion transport capability non-fluorinated aromatic polymer-based (especially under low-humidity conditions), insufficient durability, function-led design for applications beyond cells. Herein we briefly discuss several important challenges should be solved before could extensively adopted real-world applications. how to break through limitation phase-separation strategy on further increasing conductivity, develop proton exchange high-temperature working environments, an alkaline-resistant anion target its hydrogen We also introduce breakthroughs made these aspects during past few years suggest future directions require extra attention.

Language: Английский

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