Molecularly Engineered Covalent Organic Frameworks for Hydrogen Peroxide Photosynthesis

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

Published: Feb. 15, 2022

Synthesizing H

Language: Английский

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Linear Conjugated Polymers for Solar-Driven Hydrogen Peroxide Production: The Importance of Catalyst Stability

Journal of the American Chemical Society, Journal Year: 2021, Volume and Issue: 143(46), P. 19287 - 19293

Published: Nov. 10, 2021

Hydrogen peroxide (H

Language: Английский

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Developing Ni single-atom sites in carbon nitride for efficient photocatalytic H2O2 production

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

Published: Nov. 6, 2023

Photocatalytic two-electron oxygen reduction to produce high-value hydrogen peroxide (H2O2) is gaining popularity as a promising avenue of research. However, structural evolution mechanisms catalytically active sites in the entire photosynthetic H2O2 system remains unclear and seriously hinders development highly-active stable photocatalysts. Herein, we report high-loading Ni single-atom photocatalyst for efficient synthesis pure water, achieving an apparent quantum yield 10.9% at 420 nm solar-to-chemical conversion efficiency 0.82%. Importantly, using situ synchrotron X-ray absorption spectroscopy Raman directly observe that initial Ni-N3 dynamically transform into high-valent O1-Ni-N2 after O2 adsorption further evolve form key *OOH intermediate before finally forming HOO-Ni-N2. Theoretical calculations experiments reveal structure reduces formation energy barrier suppresses O=O bond dissociation, leading improved production activity selectivity.

Language: Английский

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Integrating Bifunctionality and Chemical Stability in Covalent Organic Frameworks via One-Pot Multicomponent Reactions for Solar-Driven H₂O₂ Production

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(5), P. 2975 - 2984

Published: Jan. 25, 2023

Multicomponent reactions (MCRs) can be used to introduce different functionalities into highly stable covalent organic frameworks (COFs). In this work, the irreversible three-component Doebner reaction is utilized synthesize four chemically quinoline-4-carboxylic acid DMCR-COFs (DMCR-1-3 and DMCR-1NH) equipped with an acid-base bifunctionality. These show superior photocatalytic H2O2 evolution (one of most important industrial oxidants) compared imine COF analogue (Imine-1). This achieved sacrificial oxidants but also in pure water under oxygen or air atmosphere. Furthermore, high photostability, durability, recyclability. MCR-COFs thus provide a viable materials' platform for solar chemical energy conversion.

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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Constructing Synergistic Triazine and Acetylene Cores in Fully Conjugated Covalent Organic Frameworks for Cascade Photocatalytic H₂O₂ Production

Chemistry of Materials, Journal Year: 2022, Volume and Issue: 34(11), P. 5232 - 5240

Published: May 16, 2022

Covalent organic frameworks (COFs) are an ideal template for photocatalytic H2O2 synthesis because of the tunable chemical structures and semiconductor properties. However, photoactivity COFs is still under-improved due to inefficient intrinsic charge generation, fast recombination photogenerated charges, limited electron transport along frameworks. Herein, spatially separated synergistic triazine acetylene units first integrated into (EBA-COF BTEA-COF) production. The spatial separation cores leads efficient suppressed recombination, C═C linkage facilitates electrons over skeletons. Both experimental computational results suggested that synergistically promote in a two-electron pathway. EBA-COF showed attractive activity with production rate 1830 μmol h–1 gcat–1, superior most other COF-based catalysts. This study provides method designing photocatalysts active sites based on vinylene-linked COFs.

Language: Английский

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Covalent Organic Frameworks Containing Dual O₂Reduction Centers for Overall Photosynthetic Hydrogen Peroxide Production

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

Published: Dec. 28, 2022

Covalent organic frameworks (COFs) are highly desirable for achieving high-efficiency overall photosynthesis of hydrogen peroxide (H2 O2 ) via molecular design. However, precise construction COFs toward photosynthetic H2 remains a great challenge. Herein, we report the crystalline s-heptazine-based (HEP-TAPT-COF and HEP-TAPB-COF) with separated redox centers efficient production from pure water. The spatially orderly active sites in HEP-COFs can efficiently promote charge separation enhance photocatalytic production. Compared HEP-TAPB-COF, HEP-TAPT-COF exhibits higher efficiency integrating dual reduction s-heptazine triazine moieties. Accordingly, bearing remarkable solar-to-chemical energy 0.65 % high apparent quantum 15.35 at 420 nm, surpassing previously reported COF-based photocatalysts.

Language: Английский

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Reaction Pathways toward Sustainable Photosynthesis of Hydrogen Peroxide by Polymer Photocatalysts

Chemistry of Materials, Journal Year: 2022, Volume and Issue: 34(10), P. 4259 - 4273

Published: May 11, 2022

Harnessing solar energy to generate hydrogen peroxide (H2O2) from H2O and O2 via artificial photosynthesis is an attractive route, as this approach only uses sunlight the input. Organic polymers have emerged a promising class of materials for solar-driven H2O2 production, owing their virtually unlimited molecular building blocks rich bond-forming reactions. This distinctive feature leads existence different reaction pathways characterized by electron transfer numbers. For overall H2O2, reduction oxidation must occur concurrently. Thus, in-depth insights into these are crucial with eventual aim steering optimize efficiency. In perspective, we primarily focus on state-of-the-art progress in developing polymer photocatalysts coupling We also present key challenges opportunities production future. offer ample molecular-level design space. They now found extensive applications photochemical Therefore, perspective serves guideline designing toward sustainable has significant implications future development broad area solar-to-chemical conversion research.

Language: Английский

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An Atomically Dispersed Mn-Photocatalyst for Generating Hydrogen Peroxide from Seawater via the Water Oxidation Reaction (WOR)

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(30), P. 16584 - 16596

Published: July 24, 2023

In this work, we have fabricated an aryl amino-substituted graphitic carbon nitride (g-C3N4) catalyst with atomically dispersed Mn capable of generating hydrogen peroxide (H2O2) directly from seawater. This new exhibited excellent reactivity, obtaining up to 2230 μM H2O2 in 7 h alkaline water and 1800 seawater under identical conditions. More importantly, the was quickly recovered for subsequent reuse without appreciable loss performance. Interestingly, unlike usual two-electron oxygen reduction reaction pathway, generation through a less common oxidation (WOR) process which both direct indirect WOR processes occurred; namely, photoinduced h+ oxidized H2O via one-step 2e- WOR, first hydroxide (OH-) ion generate hydroxy radical (•OH), formed indirectly by combination two •OH. We characterized material, at catalytic sites, atomic level using electron paramagnetic resonance, X-ray absorption near edge structure, extended fine high-resolution transmission microscopy, photoelectron spectroscopy, magic-angle spinning solid-state NMR multiscale molecular modeling, combining classical reactive dynamics simulations quantum chemistry calculations.

Language: Английский

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Design Principles and Strategies of Photocatalytic H₂O₂ Production from O₂ Reduction

ACS ES&T Engineering, Journal Year: 2022, Volume and Issue: 2(6), P. 1068 - 1079

Published: Jan. 25, 2022

H2O2, as an important chemical and environmentally friendly oxidant, has been applied in various fields, such synthesis, pulp bleaching, disinfection, environmental remediation. Nevertheless, the industrial anthraquinone process for production of H2O2 is energy-intensive only suitable centralized H2O2. Photocatalytic from O2 reduction a promising approach on-site decentralized synthesis. Although photocatalysts have developed, efficiency still limited by narrow light absorption range, rapid charge recombination, slow surface reaction. In this perspective, we briefly introduce basic mechanism photocatalytic reduction. Subsequently, propose design principles discuss universal strategies enhancing performance production, aspects absorption, separation, catalytic reaction, reactor configurations. Finally, present our prospects suggestions development future. We hope that perspective can provide useful guidance rational efficient novel advance both insights practical applications production.

Language: Английский

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