Photocatalytic Molecular Oxygen Activation by Regulating Excitonic Effects in Covalent Organic Frameworks

Journal of the American Chemical Society, Journal Year: 2020, Volume and Issue: 142(49), P. 20763 - 20771

Published: Nov. 23, 2020

Excitonic effects caused by Coulomb interactions between electrons and holes play subtle significant roles on photocatalysis, yet have been long ignored. Herein, porphyrinic covalent organic frameworks (COFs, specifically DhaTph-M), in the absence or presence of different metals porphyrin centers, shown as ideal models to regulate excitonic effects. Remarkably, incorporation Zn2+ COF facilitates conversion singlet triplet excitons, whereas Ni2+ introduction promotes dissociation excitons hot carriers under photoexcitation. Accordingly, discriminative behavior DhaTph-Zn DhaTph-Ni enables activation O2 1O2 O2•–, respectively, visible light irradiation, resulting distinctly activity selectivity photocatalytic terpinene oxidation. Benefiting from these results, exhibits excellent O2•–-engaged hydroxylation boronic acid, while possesses superior performance 1O2-mediated selective oxidation sulfides. This work provides in-depth insights into molecular oxygen opens an avenue regulation based COFs.

Language: Английский

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Strongly Reducing (Diarylamino)benzene-Based Covalent Organic Framework for Metal-Free Visible Light Photocatalytic H₂O₂ Generation

Journal of the American Chemical Society, Journal Year: 2020, Volume and Issue: 142(47), P. 20107 - 20116

Published: Nov. 13, 2020

Photocatalytic reduction of molecular oxygen is a promising route toward sustainable production hydrogen peroxide (H2O2). This challenging process requires photoactive semiconductors enabling solar energy driven generation and separation electrons holes with high charge transfer kinetics. Covalent organic frameworks (COFs) are an emerging class semiconductors, tunable at level for carrier transfer. Herein, we report two newly designed two-dimensional COFs based on (diarylamino)benzene linker that form Kagome (kgm) lattice show strong visible light absorption. Their crystallinity large surface areas (up to 1165 m2·g-1) allow efficient diffusion. The diarylamine (donor) unit promotes properties, these efficiently reduce H2O2. Overall, the use metal-free, recyclable photocatalytic system allows transformations.

Language: Английский

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A Crystalline Partially Fluorinated Triazine Covalent Organic Framework for Efficient Photosynthesis of Hydrogen Peroxide

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 61(19)

Published: March 1, 2022

A partially fluorinated, metal-free, imine-linked two-dimensional triazine covalent organic framework (TF50 -COF) photocatalyst was developed. Fluorine (F)-substituted and nonsubstituted units were integrated in equimolar amounts on the edge aromatic units, where they mediated two-electron O2 photoreduction. F-substitution created an abundance of Lewis acid sites, which regulated electronic distribution adjacent carbon atoms provided highly active sites for adsorption, widened visible-light-responsive range catalyst, while enhancing charge separation. Varying proportion F maximized interlayer interactions TF50 -COF, resulting improved crystallinity with faster carrier transfer robust photostability. The -COF catalyst demonstrates high selectivity stability photoreduction into H2 , a yield rate 1739 μmol h-1 g-1 remarkable apparent quantum efficiency 5.1 % at 400 nm, exceeding performance previously reported nonmetal COF-based photocatalysts.

Language: Английский

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Porous organic polymers for light-driven organic transformations

Chemical Society Reviews, Journal Year: 2022, Volume and Issue: 51(7), P. 2444 - 2490

Published: Jan. 1, 2022

As a new generation of porous materials, organic polymers (POPs), have recently emerged as powerful platform heterogeneous photocatalysis. POPs are constructed using extensive synthesis methodologies, with various functional units being connected via high-energy covalent bonds. This review systematically presents the recent advances in for visible-light driven transformations. Herein, we firstly summarize common construction strategies POP-based photocatalysts based on two major approaches: pre-design and post-modification; secondly, categorize methods reaction types constructing POPs. We then classify introduce specific reactions current light-driven POP-mediated Finally, outline state development problems faced transformations by POPs, present some perspectives to motivate reader explore solutions these confront challenges process.

Language: Английский

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Three-Component Donor−π–Acceptor Covalent–Organic Frameworks for Boosting Photocatalytic Hydrogen Evolution

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(15), P. 8364 - 8374

Published: March 14, 2023

Two-dimensional covalent-organic frameworks (2D COFs) have recently emerged as great prospects for their applications new photocatalytic platforms in solar-to-hydrogen conversion; nevertheless, inefficient solar energy capture and fast charge recombination hinder the improvement of hydrogen production performance. Herein, two photoactive three-component donor-π-acceptor (TCDA) materials were constructed using a multicomponent synthesis strategy by introducing electron-deficient triazine electron-rich benzotrithiophene moieties into through sp2 carbon imine linkages, respectively. Compared with two-component COFs, novel TCDA-COFs are more convenient regulating inherent photophysical properties, thereby realizing outstanding activity evolution from water. Remarkably, first carbon-linked TCDA-COF displays an impressive rate 70.8 ± 1.9 mmol g-1 h-1 excellent reusability presence 1 wt % Pt under visible-light illumination (420-780 nm). Utilizing combination diversified spectroscopy theoretical prediction, we show that full π-conjugated linkage not only effectively broadens harvesting COFs but also enhances transfer separation efficiency.

Language: Английский

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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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Heterogeneous Photocatalytic Organic Transformation Reactions Using Conjugated Polymers-Based Materials

ACS Catalysis, Journal Year: 2020, Volume and Issue: 10(20), P. 12256 - 12283

Published: Sept. 24, 2020

Photocatalytic heterogeneous organic transformation is considered as an efficient, clean atomic economy, and low-energy consumption strategy for synthesis. Conjugated polymers (CPs)-based materials have recently shown great potential diverse photocatalytic applications because of their unique properties, such structural designability, recyclability, high chemical stability, low cost, they emerged promising alternatives to traditional molecular or inorganic photocatalyst in photoredox reactions. Immense efforts been made toward the construction CPs-based versatile transformations. In this Review, we aim summarize recent progress photocatalysts transformations including oxidation, reduction, coupling, cycloaddition reaction. This Review discusses influence molecular, electronic, channel structure on light absorption, charge separation, mass transfer different The regulated synthesis, mechanistic discussions, future challenges systems are also considered. It expected that could not only deepen comprehension but open up inspirations feasibilities materials.

Language: Английский

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2D Conjugated Covalent Organic Frameworks: Defined Synthesis and Tailor-Made Functions

Accounts of Chemical Research, Journal Year: 2022, Volume and Issue: 55(6), P. 795 - 808

Published: Jan. 13, 2022

ConspectusCovalent organic frameworks (COFs) are an emerging class of crystalline porous polymers and have received tremendous attention research interest. COFs can be classified into two-dimensional (2D) three-dimensional (3D) analogues. Resembling the architectures graphene, 2D conjugated exhibited promising prospects in many fields, such as gas storage separation, heterogeneous catalysis, sensing, photocatalysis, environmental remediation, drug delivery, energy conversion, so forth. However, efficient structural design for high-throughput production remains challenging.In this Account, we summarize our recent contributions to design, synthesis, application exploration COFs. First, raised "two-in-one" strategy facile synthesis imine with good reproducibility solvent adaptability. Thanks elaborate molecular strategy, could easily modulate topology fabricate COF films. In addition, developed two approaches stabilize by using planar building blocks donor-acceptor structures. We also proposed a skeleton engineering electrode materials, through which redox-active orthoquinone moieties were stepwise-incorporated skeletons isostructural imine-linked This enabled systematic investigations on series analogous structures but different numbers active sites storage, provides platform unveil underlying structure-property relationships. recently new kind arylamine-linked The electroactive diphenylamine linkages endowed these extended conjugation improved stability, conferred excellent pseudocapacitive performance. Moreover, tailor-made sulfur-rich introduced that synthesized selective introduction polysulfide or sulfonyl groups used Li proton conduction. At end, key challenges toward practical applications their future suggested. hope Account will evoke inspirations innovative work field near future, especially some burgeoning interdisciplinary areas.

Language: Английский

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Engineering β-ketoamine covalent organic frameworks for photocatalytic overall water splitting

Nature Communications, Journal Year: 2023, Volume and Issue: 14(1)

Published: Feb. 3, 2023

Covalent organic frameworks (COFs) are an emerging type of crystalline and porous photocatalysts for hydrogen evolution, however, the overall water splitting activity COFs is rarely known. In this work, we firstly realized β-ketoamine by systematically engineering N-sites, architecture, morphology. By in situ incorporating sub-nanometer platinum (Pt) nanoparticles co-catalyst into pores nanosheets, both Pt@TpBpy-NS Pt@TpBpy-2-NS show visible-light-driven activity, with optimal H

Language: Английский

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Fabrication of Robust Covalent Organic Frameworks for Enhanced Visible-Light-Driven H₂ Evolution

ACS Catalysis, Journal Year: 2021, Volume and Issue: 11(4), P. 2098 - 2107

Published: Feb. 2, 2021

Developing photocatalysts capable of visible-light-driven water splitting to produce clean hydrogen (H2) is one the premier challenges for solar energy conversion into and sustainable fuels. Inspired from structure feature photosystem I in nature, we have designed synthesized a series robust covalent organic frameworks (NKCOFs = Nankai University COFs) based on electric donor–acceptor moieties, which electron-donor group pyrene can be used harvesting light. Meanwhile, benzothiadiazole with different functional groups was introduced as an electron acceptor tune light-adsorption ability COFs. Notably, activity NKCOF-108 photochemical H2 evolution under visible light among highest COFs without hybridization other materials. We attribute high rate its distinct structural features wide visible-light-response range. The highly ordered layered ensures that sufficient active sites are accessible production, design promote separation photogenerated carriers. Our findings provided effective strategy light-driven evolution.

Language: Английский

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