Photocatalytic Hydrogen Production on a sp²‐Carbon‐Linked Covalent Organic Framework

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 61(42)

Published: Aug. 27, 2022

Abstract Two‐dimensional covalent organic frameworks (2D‐COFs) have emerged as attractive platforms for solar‐to‐chemical energy conversion. In this study, we implemented a gradient heating strategy to synthesize sp 2 ‐carbon‐linked triazine‐based COF, COF‐JLU100, exhibiting high crystallinity, large surface area, good durability and carrier mobility solar‐driven photocatalytic hydrogen evolution. The Pt‐doped COF‐JLU100 demonstrated evolution rate of over 100 000 μmol g −1 h water splitting under visible‐light illumination (λ>420 nm). Experimental theoretical studies corroborate that the cyano‐vinylene segments in extend π‐delocalization enable fast charge transfer separation rates well dispersion water. Moreover, can be prepared by low‐cost easily available monomers has excellent stability, which is desirable practical production.

Language: Английский

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The effect of enantioselective chiral covalent organic frameworks and cysteine sacrificial donors on photocatalytic hydrogen evolution

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

Published: Oct. 1, 2022

Abstract Covalent organic frameworks (COFs) have constituted an emerging class of photocatalysts showing enormous potential for visible photocatalytic H 2 evolution from water. However, suffering sluggish reaction kinetics, COFs often cooperate with precious metal co-catalysts essential proton-reducing capability. Here, we synthesize a chiral β-ketoenamine-linked COF coordinated 10.51 wt% atomically dispersed Cu(II) as electron transfer mediator. The enantioselective combination the COF-Cu(II) skeleton L-/D-cysteine sacrificial donors remarkably strengthens hole extraction and in turn, photoinduced electrons accumulate rapidly via Cu ions. Also, parallelly stacking sequence provides energetically favorable arrangement H-adsorbed sites. Thus, without metal, rate reaches high 14.72 mmol h −1 g enantiomeric mixtures. This study opens up strategy optimizing kinetics promises exciting photocatalysis.

Language: Английский

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Research Progress in Donor−Acceptor Type Covalent Organic Frameworks

Advanced Materials, Journal Year: 2023, Volume and Issue: 35(48)

Published: April 24, 2023

Covalent organic frameworks (COFs) are new porous materials constructed by covalent bonds, with the advantages of pre-designable topology, adjustable pore size, and abundant active sites. Many research studies have shown that COFs exhibit great potential in gas adsorption, molecular separation, catalysis, drug delivery, energy storage, etc. However, electrons holes intrinsic COF prone to compounding transport, carrier lifetime is short. The donor-acceptor (D-A) type COFs, which synthesized introducing D A units into backbone, combine separated electron hole migration pathway, tunable band gap optoelectronic properties D-A polymers unique made progress related recent years. Here, synthetic strategies first outlined, including rational design linkages as well functionalization approaches. Then applications catalytic reactions, photothermal therapy, electronic systematically summarized. In final section, current challenges, directions for development presented.

Language: Английский

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The order–disorder conundrum: a trade-off between crystalline and amorphous porous organic polymers for task-specific applications

Journal of Materials Chemistry A, Journal Year: 2022, Volume and Issue: 10(33), P. 17077 - 17121

Published: Jan. 1, 2022

The review unravels the order–disorder conundrum in porous organic polymers view of task-specific applications through a comparative deliberation.

Language: Английский

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Recent progress of covalent organic frameworks membranes: Design, synthesis, and application in water treatment

Eco-Environment & Health, Journal Year: 2023, Volume and Issue: 2(3), P. 117 - 130

Published: July 13, 2023

To date, significant efforts have been devoted to eliminating hazardous components purify wastewater through the development of various nanomaterials. Covalent organic frameworks (COFs), an important branch porous crystalline family, possess peculiarity ultrahigh surface area, adjustable pore size, and facile functionality. Exciting studies from design fabrication potential applications in water treatment by COF-based membranes (COMs) emerged. This review summarizes preparation strategies synthesis mechanisms for COMs, including layer-by-layer stacking, situ growth, interfacial polymerization, electrochemical synthesis, briefly describes advanced characterization techniques COMs. Moreover, application COMs heavy metal removal, dye separation, purification radionuclides, pollutant detection, sea desalination, so on, is described discussed. Finally, perspectives on future opportunities designing proposed.

Language: Английский

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Effect of Controlling Thiophene Rings on D-A Polymer Photocatalysts Accessed via Direct Arylation for Hydrogen Production

Molecules, Journal Year: 2023, Volume and Issue: 28(11), P. 4507 - 4507

Published: June 1, 2023

Conjugated polymer photocatalysts for hydrogen production have the advantages of an adjustable structure, strong response in visible light region, energy levels, and easy functionalization. Using atom- step-economic direct C–H arylation method, dibromocyanostilbene was polymerized with thiophene, dithiophene, terthiophene, fused thienothiophene dithienothiophene, respectively, to produce donor–acceptor (D-A)-type linear conjugated polymers containing different thiophene derivatives conjugation lengths. Among them, D-A photocatalyst constructed from dithienothiophene could significantly broaden spectral response, a evolution rate up 12.15 mmol h−1 g−1. The results showed that increase number rings on building blocks beneficial photocatalytic cyanostyrylphene-based polymers. For unfused dithiophene enabled more rotation freedom between reduced intrinsic charge mobility, resulting lower performance accordingly. This study provides suitable process design electron donors photocatalysts.

Language: Английский

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Covalent organic frameworks in heterogeneous catalysis: recent advances and future perspective

Materials Chemistry Frontiers, Journal Year: 2023, Volume and Issue: 7(16), P. 3298 - 3331

Published: Jan. 1, 2023

This review provides an overview of the recent advances in heterogeneous catalysis using COFs, primarily from 2020 to 2023, covering fundamentals, advantages, current challenges, and future perspectives.

Language: Английский

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Strategic design of covalent organic frameworks (COFs) for photocatalytic hydrogen generation

Journal of Materials Chemistry A, Journal Year: 2023, Volume and Issue: 11(27), P. 14489 - 14538

Published: Jan. 1, 2023

Covalent organic frameworks provide a platform for the integration of functional linkers into ordered yet tunable two-dimensional to yield π–π stacked conjugated materials photocatalytic water splitting hydrogen generation.

Language: Английский

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Monolayer-Assisted Surface-Initiated Schiff-Base-Mediated Aldol Polycondensation for the Synthesis of Crystalline sp² Carbon-Conjugated Covalent Organic Framework Thin Films

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(9), P. 5203 - 5210

Published: Feb. 13, 2023

sp2 carbon-conjugated covalent organic frameworks (sp2c-COFs) with superb in-plane π-conjugations, high chemical stability, and robust framework structure are expected to be ideal films/membranes for a wide range of applications including energy-related devices optoelectronics. However, so far, sp2c-COFs have been mainly limited microcrystalline powders, this consequently hampered their performances in devices. Herein, we report simple methodology fabricate large-area, free-standing, crystalline sp2c-COF films (TFPT–TMT TB–TMT) on various solid substrates (e.g., fluorine-doped tin oxide, aluminum sheet, polyacrylonitrile membrane) by self-assembly monolayer-assisted surface-initiated Schiff-base-mediated aldol polycondensation (namely, SI-SBMAP). The resultant show lateral sizes up 120 cm2 tunable thickness from tens nanometers few micrometers. Owing the highly ordered quasi-1D channels, membrane-based osmotic power generator presents an output density 14.1 W m–2 under harsh conditions, outperforming most reported COF membranes as well commercialized benchmark (5 m–2). This work demonstrates interfacial fabrication green energy potential

Language: Английский

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Oligo(phenylenevinylene)‐Based Covalent Organic Frameworks with Kagome Lattice for Boosting Photocatalytic Hydrogen Evolution

Advanced Materials, Journal Year: 2023, Volume and Issue: 36(1)

Published: Oct. 2, 2023

Covalent organic frameworks (COFs) have shown great advantages as photocatalysts for hydrogen evolution. However, the effect of linkage geometry and type on extent π-electron conjugation in plane framework photocatalytic properties COFs remains a significant challenge. Herein, two Kagome (kgm) topologic oligo(phenylenevinylene)-based are designed synthesized boosting evolution via "two one" strategy. Under visible light irradiation, COF-954 with 5 wt% Pt cocatalyst exhibits high rate (HER) 137.23 mmol g

Language: Английский

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