Covalent organic frameworks for photocatalysis: Synthesis, structural features, fundamentals and performance

Coordination Chemistry Reviews, Journal Year: 2022, Volume and Issue: 475, P. 214889 - 214889

Published: Oct. 15, 2022

Language: Английский

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Metalated covalent organic frameworks: from synthetic strategies to diverse applications

Chemical Society Reviews, Journal Year: 2022, Volume and Issue: 51(15), P. 6307 - 6416

Published: Jan. 1, 2022

This review highlights the recent advances of metalated covalent organic frameworks, including synthetic strategies and applications, discusses current challenges future directions.

Language: Английский

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Covalent Organic Framework Based Functional Materials: Important Catalysts for Efficient CO₂Utilization

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 61(15)

Published: Jan. 21, 2022

As hot topics in the chemical conversion of CO2 , photo-/electrocatalytic reduction and use as a supporter for energy storage have shown great potential utilization . However, many obstacles still exist on road to realizing highly efficient conversion, such inefficient uptake/activation mass transport catalysts. Covalent organic frameworks (COFs), kind porous material, been widely explored catalysts owing their unique features. In particular, COF-based functional materials containing diverse active sites (such single metal sites, nanoparticles, oxides) offer storage. This Minireview discusses recent breakthroughs basic knowledge, mechanisms, pathways strategies that addition, challenges prospects are also introduced.

Language: Английский

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Oxidation‐Reduction Molecular Junction Covalent Organic Frameworks for Full Reaction Photosynthesis of H₂O₂

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 62(9)

Published: Dec. 30, 2022

The full reaction photosynthesis of H2 O2 that can combine water-oxidation and oxygen-reduction without sacrificial agents is highly demanded to maximize the light-utilization overcome complex reaction-process anthraquinone-oxidation. Here, a kind oxidation-reduction molecular junction covalent-organic-framework (TTF-BT-COF) has been synthesized through covalent-coupling tetrathiafulvalene (photo-oxidation site) benzothiazole (photo-reduction site), which presents visible-light-adsorption region, effective electron-hole separation-efficiency photo-redox sites enables generation . Specifically, record-high yield (TTF-BT-COF, ≈276 000 μM h-1 g-1 ) for achieved among porous crystalline photocatalysts. This first work design COFs , might extend scope in production.

Language: Английский

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Transformation of Porous Organic Cages and Covalent Organic Frameworks with Efficient Iodine Vapor Capture Performance

Journal of the American Chemical Society, Journal Year: 2022, Volume and Issue: 144(27), P. 12390 - 12399

Published: June 29, 2022

The reaction of 5,5′-([2,2′-bipyridine]-5,5′-diyl)diisophthalaldehyde (BPDDP) with cyclohexanediamine and [benzidine (BZ)/[2,2′-bipyridine]-5,5′-diamine (BPDA)], respectively, affords a nitrogen-rich porous organic cage BPPOC two two-dimensional (2D) covalent frameworks (COFs), USTB-1 USTB-2 (USTB = University Science Technology Beijing), under suitable conditions. Interestingly, single-crystal X-ray diffraction structure is able to successfully transform into (newly converted COFs denoted as USTB-1c USTB-2c, respectively) upon exchange the imine unit in by BZ BPDA. Such transformation also enables isolation analogous (USTB-3c USTB-4c) on basis an isostructural cage, BTPOC, which derived from 5,5′-([2,2′-bithiophene]-4,4′-diyl)diisophthalaldehyde (BTDDP) cyclohexanediamine. However, conventional solvothermal between BTDDP BPDA leads impure phase USTB-4 containing incompletely aldehyde groups due limited solubility building block. newly prepared have been characterized nuclear magnetic resonance spectroscopy, Fourier infrared scanning electron microscopy, transmission microscopy. In particular, absorb iodine vapor uptake 5.64 g g–1, breaking cage's (POC's) record value 3.78 g–1. Nevertheless, cage-derived exhibit improved adsorption capability comparison directly synthesized counterparts, highest 5.80 g–1 for USTB-1c. mechanism investigation unveils superiority nitrogen atoms sulfur POCs capture assistance definite crystal structures. This, combination porosity, synergistically influences capacity COFs.

Language: Английский

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A Stable and Conductive Covalent Organic Framework with Isolated Active Sites for Highly Selective Electroreduction of Carbon Dioxide to Acetate

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 61(36)

Published: June 13, 2022

Electroreduction of CO2 to acetate provides a promising strategy reduce emissions and store renewable energy, but is usually by-product. Here, we show stable conductive two-dimensional phthalocyanine-based covalent-organic framework (COF) as an electrocatalyst for reduction with single-product Faradaic efficiency (FE) 90.3(2)% at -0.8 V (vs. RHE) current density 12.5 mA cm-2 in 0.1 M KHCO3 solution. No obvious degradation was observed over 80 hours continuous operation. Combined the comparison properties other catalysts isolated metal active sites, theoretical calculations situ infrared spectroscopy revealed that copper-phthalocyanine site high electron conducive key step C-C coupling *CH3 produce acetate, can avoid *CO or *CHO ethylene ethanol.

Language: Английский

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In Situ Synthesis of Chemically Bonded 2D/2D Covalent Organic Frameworks/O‐Vacancy WO₃ Z‐Scheme Heterostructure for Photocatalytic Overall Water Splitting

Advanced Materials, Journal Year: 2023, Volume and Issue: 35(33)

Published: June 15, 2023

Abstract Covalent organic frameworks (COFs) have shown great promise for photocatalytic hydrogen evolution via water splitting. However, the four‐electron oxidation of remains elusive toward oxygen evolution. Enabling this pathway is critical to improve yield and maximize atom utilization efficiency. A Z‐scheme heterojunction proposed overcoming fundamental issues in COF‐based overall splitting (OWS), such as inefficient light absorption, charge recombination, poor ability. It that construction a novel 2D/2D through situ growth COFs on O‐vacancy WO 3 nanosheets (Ov‐WO ) WOC chemical bond can remarkably promote OWS. Benefiting from synergistic effect between enhanced built‐in electric field by interfacial bond, strong ability Ov‐WO 3, ultrathin structure TSCOF, both separation efficiency photogenerated electron–hole pairs be significantly enhanced. An impressive half‐rection rate 593 mmol h −1 g 146 (hydrogen) 68 (oxygen) µmol are achieved COF‐WO (TSCOFW) composite. This with two‐step excitation precisely cascaded charge‐transfer makes it responsible efficient solar‐driven OWS without sacrificial agent.

Language: Английский

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In Situ Reconstruction of Cu–N Coordinated MOFs to Generate Dispersive Cu/Cu₂O Nanoclusters for Selective Electroreduction of CO₂to C₂H₄

ACS Catalysis, Journal Year: 2022, Volume and Issue: 12(24), P. 15230 - 15240

Published: Nov. 29, 2022

Electrochemical reduction of CO2 to obtain high-value-added feedstocks is a promising strategy alleviate the energy crisis. Cu-based catalysts generate multi-carbon products with high activity in reaction (CO2RR), although great challenges remain selectivity and stability catalysts. Here, highly active Cu/Cu2O nanoclusters were produced via situ electrochemical reconstruction using Cu–N coordinated MOFs as precursors for selective C2H4 synthesis, showing Faradaic efficiency 70.2 ± 1.7% toward partial current density 12.38 mA·cm–2 at −1.03 V vs RHE CO2RR. In infrared spectroscopy observation *CO*CO *CO*COH intermediates confirmed formation pathway, while Raman spectroscopy, ex XPS, HRTEM evidenced that coexisting Cu2O Cu sites. The method could be used synthesize electroreduction.

Language: Английский

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Efficient Photocatalytic Hydrogen Evolution by Modulating Excitonic Effects in Ni‐Intercalated Covalent Organic Frameworks

Advanced Energy Materials, Journal Year: 2023, Volume and Issue: 13(13)

Published: Feb. 15, 2023

Abstract Covalent organic frameworks (COFs) as appealing platforms have received tremendous interest in the field of photocatalytic H 2 evolution owing to their well‐defined structures and tailor‐made function. However, excitonic effects resulting from Coulomb interactions between electron–hole pairs are key rate‐determining processes hydrogen evolution, which usually ignored. Thus, it is profound significance highly desired, but still a challenge, explore new routes modulate dissociation COFs for boosting photocatalysis. To address this Ni‐intercalated fluorenone‐based (Ni‐COF‐SCAU‐1) at imine linkage, proposed first time, demonstrated exhibit enhanced polarization electric field; thus, facilitating Hall electron mobility singlet excitons into free charge carriers under photoexcitation participate surface reaction. Benefiting these results, Ni‐COF‐SCAU‐1 displays production rate 197.46 mmol·g −1 h visible light irradiation with an apparent quantum efficiency (AQE) up 43.2% 420 nm. This work offers in‐depth understanding crucial role interlayer atomic interface improving paves way regulation COFs.

Language: Английский

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Constructing Chiral Covalent‐Organic Frameworks for Circularly Polarized Light Detection

Advanced Materials, Journal Year: 2023, Volume and Issue: 36(17)

Published: Aug. 17, 2023

Abstract The use of chiral covalent organic frameworks (COFs) as active elements in photodetectors to directly identify circularly polarized light (CPL) can meet the requirement integration and miniaturization as‐fabricated devices. Herein, design synthesis two isoreticular two‐dimensional (2D) COFs (CityU‐7 CityU‐8) by introducing photosensitive porphyrin‐based amines (5,10,15,20‐tetrakis(4‐aminophenyl)porphyrin) enhance optical absorption aldehyde linkage (2,5‐bis((S/R))‐2‐methylbutoxy)terephthalaldehyde) engender chirality for direct CPL detection are reported. Their crystalline structures were confirmed powder X‐ray diffraction, Fourier‐transform infrared spectroscopy, low‐dose transition electron microscopy. Employing both layers photodetectors, left‐handed (LHC) right‐handed (RHC) at 405 nm be well distinguishable with short response time, high responsivity, satisfying detectivity. study provides first example on CPL.

Language: Английский

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