Optoelectronic processes in covalent organic frameworks

Chemical Society Reviews, Год журнала: 2020, Номер 50(3), С. 1813 - 1845

Опубликована: Дек. 17, 2020

Covalent organic frameworks (COFs) are crystalline porous materials constructed from molecular building blocks using diverse linkage chemistries. Their modular construction system allows not only for tailor-made design but also an immense variety of blocks, opening the door to numerous different functionalities and potential applications. As a consequence, large number that can act as light-harvesters, semiconductors, ligands, binding sites or redox centers have recently been integrated into scaffolds COFs. This unique combination reticular chemistry with control intrinsic properties paves way towards new semiconducting (opto-)electronic applications such sensors, photocatalysts -electrodes, supercapacitor battery materials, solar-harvesting devices light emitting diodes. With developments regarding motif, highly stable still tunable COFs developed even under harsh conditions. Further, stacking modes distances in investigated powerful means optical electrical characteristics these self-assembled frameworks. Advanced understanding optoelectronic processes has enabled their implementation promising real-world review highlights key concepts synthesis electro- photoactive well our frameworks, hence establishing paradigm rational well-defined novel devices.

Язык: Английский

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Covalent organic frameworks

Nature Reviews Methods Primers, Год журнала: 2023, Номер 3(1)

Опубликована: Янв. 12, 2023

Язык: Английский

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Regenerable Covalent Organic Frameworks for Photo‐enhanced Uranium Adsorption from Seawater

Angewandte Chemie International Edition, Год журнала: 2020, Номер 59(40), С. 17684 - 17690

Опубликована: Июнь 25, 2020

Abstract Uranium is a key resource for the development of nuclear industry, and extracting uranium from natural seawater one most promising ways to address shortage resources. Herein, semiconducting covalent organic framework (named NDA‐TN‐AO) with excellent photocatalytic photoelectric activities was synthesized. The effect endowed NDA‐TN‐AO high anti‐biofouling activity by generating biotoxic reactive oxygen species promoting photoelectrons reduce adsorbed U VI insoluble IV , thereby increasing extraction capacity. Owing photoinduced effect, adsorption capacity in reaches 6.07 mg g −1 which 1.33 times that dark. enhanced material seawater.

Язык: Английский

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Amidoxime-based materials for uranium recovery and removal

Journal of Materials Chemistry A, Год журнала: 2020, Номер 8(16), С. 7588 - 7625

Опубликована: Янв. 1, 2020

This review provides a comprehensive overview of amidoxime-based materials for uranium recovery and removal from the perspectives synthesis, characterizations, types, influence factors, binding mechanisms, cost evaluation.

Язык: Английский

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Fully Conjugated Donor–Acceptor Covalent Organic Frameworks for Photocatalytic Oxidative Amine Coupling and Thioamide Cyclization

ACS Catalysis, Год журнала: 2020, Номер 10(15), С. 8717 - 8726

Опубликована: Июль 10, 2020

Covalent organic frameworks (COFs) are promising candidates as heterogeneous photocatalysts because of their porosity and tunable light absorption. The photostability charge separation COFs highly important to improve the efficiency photocatalytic transformation. In this work, a fully conjugated donor–acceptor COF is constructed with benzothiadiazole unit, which exhibits high stability enhanced separation. prepared can efficaciously produce superoxide radical anions under air visible light, mediate oxidative amine coupling cyclization thioamide 1,2,4-thiadiazole in moderate yield recyclability (18 examples). This study demonstrates great capacity D–A structure for light-driven synthesis.

Язык: Английский

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Covalent Organic Polymers and Frameworks for Fluorescence-Based Sensors

ACS Sensors, Год журнала: 2021, Номер 6(4), С. 1461 - 1481

Опубликована: Апрель 7, 2021

Following the advancements and diversification in synthetic strategies for porous covalent materials literature, science community started to investigate performance of organic polymers (COPs) frameworks (COFs) applications that require large surface areas interaction with other molecules, chemical stability, insolubility. Sensorics is an area where COPs COFs have demonstrated immense potential achieved high levels sensitivity selectivity on account their tunable structures. In this review, we focus those polymeric systems use fluorescence spectroscopy as a method detection. After briefly reviewing physical basis fluorescence-based sensors, delve into various kinds analytes been explored COFs, namely, heavy metal ions, explosives, biological amines, pH, volatile compounds solvents, iodine, enantiomers, gases, anions. Throughout work, discuss mechanisms involved each sensing application aim quantify potency discussed sensors by providing limits detection quenching constants when available. This review concludes summary surveyed literature raises few concerns should be addressed future development COP COF sensors.

Язык: Английский

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Tuning excited state electronic structure and charge transport in covalent organic frameworks for enhanced photocatalytic performance

Nature Communications, Год журнала: 2023, Номер 14(1)

Опубликована: Фев. 27, 2023

Covalent organic frameworks (COFs) represent an emerging class of photocatalysts. However, their complicated structures lead to indeterminacy about photocatalytic active sites and reaction mechanisms. Herein, we use reticular chemistry construct a family isoreticular crystalline hydrazide-based COF photocatalysts, with the optoelectronic properties local pore characteristics COFs modulated using different linkers. The excited state electronic distribution transport pathways in are probed host experimental methods theoretical calculations at molecular level. One our developed (denoted as COF-4) exhibits remarkable electron utilization efficiency charge transfer properties, achieving record-high uranium extraction performance ~6.84 mg/g/day natural seawater among all techniques reported so far. This study brings new understanding operation COF-based guiding design improved photocatalysts for many applications.

Язык: Английский

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Functionalized Iron–Nitrogen–Carbon Electrocatalyst Provides a Reversible Electron Transfer Platform for Efficient Uranium Extraction from Seawater

Advanced Materials, Год журнала: 2021, Номер 33(51)

Опубликована: Окт. 4, 2021

Uranium extraction from seawater provides an opportunity for sustainable fuel supply to nuclear power plants. Herein, adsorption-electrocatalysis strategy is demonstrated efficient uranium using a functionalized iron-nitrogen-carbon (Fe-Nx -C-R) catalyst, comprising N-doped carbon capsules supporting FeNx single-atom sites and surface chelating amidoxime groups (R). The bring hydrophilicity the adsorbent offer surface-specific binding UO22+ capture. site-isolated centres reduce adsorbed UO2+ . Subsequently, through electrochemical reduction of sites, unstable U(V) ions are reoxidized U(VI) in presence Na+ resulting generation solid Na2 O(UO3 ·H2 O)x , which can easily be collected. Fe-Nx -C-R reduced concentration ≈3.5 ppb below 0.5 with calculated capacity ≈1.2 mg g-1 within 24 h. To best knowledge, developed system first use adsorption uranyl electrodeposition .H2 seawater. important discoveries guide technology development

Язык: Английский

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Vinylene‐Linked Covalent Organic Frameworks (COFs) with Symmetry‐Tuned Polarity and Photocatalytic Activity

Angewandte Chemie International Edition, Год журнала: 2020, Номер 59(52), С. 23845 - 23853

Опубликована: Сен. 21, 2020

Abstract The polarity of a semiconducting molecule affects its intrinsic photophysical properties, which can be tuned by varying the molecular geometry. Herein, we developed D 3 h ‐symmetric tricyanomesitylene as new monomer could reticulated into vinylene‐linked covalent organic framework (g‐C 54 N 6 ‐COF) via Knoevenagel condensation with another 2,4,6‐tris(4′‐formyl‐biphenyl‐4‐yl)‐1,3,5‐triazine. Replacing C 2 v 3,5‐dicyano‐2,4,6‐trimethylpyridine gave less‐symmetric COF 52 ‐COF). octupolar conjugated characters g‐C ‐COF were reflected in scarce solvatochromic effects either ground or excited states, and endowed it more promising behavior compared ‐COF, such enhanced light‐harvesting excellent photo‐induced charge generation separation. Along matched energy level, enabled two‐half reactions photocatalytic water splitting an average O evolution rate 51.0 μmol −1 g H 2518.9 . Such values are among highest state‐of‐the‐art photocatalysts.

Язык: Английский

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Extremely stable amidoxime functionalized covalent organic frameworks for uranium extraction from seawater with high efficiency and selectivity

Science Bulletin, Год журнала: 2021, Номер 66(19), С. 1994 - 2001

Опубликована: Май 16, 2021

Язык: Английский

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