Π‐Skeleton Tailoring of Olefin‐Linked Covalent Organic Frameworks Achieving Low Exciton Binding Energy for Photo‐Enhanced Uranium Extraction from Seawater

Advanced Functional Materials, Journal Year: 2023, Volume and Issue: 34(1)

Published: Sept. 21, 2023

Abstract Adsorption‐photocatalysis technology based on covalent organic frameworks (COFs) offers an alternative method for advancing the field of uranium extraction from seawater. When determining photocatalytic activity COFs, binding energy excitons ( E b ) functions is decisive factor. Nevertheless, majority reported COFs have a large , which seriously restricts their application in photocatalysis. Using practical π‐skeleton engineering strategy, current study synthesizes three donor‐acceptor olefin‐linked containing amidoxime units effort to minimize . Theoretical and experimental results reveal that construction planar continuous π ‐electron delocalization channels can significantly reduce promote separation electron‐hole pairs, thereby enhancing activities. Moreover, TTh‐COF‐AO with ‐skeleton donor reduced, exhibits substantially smaller (38.4 meV). Under visible light irradiation, high photo‐enhanced capacity 10.24 mg g −1 achieved natural seawater without addition sacrificial reagents, superior been date. This study, therefore, paves way development tailored, efficient photocatalysts

Language: Английский

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Reversing Free‐Electron Transfer of MoS_2+x Cocatalyst for Optimizing Antibonding‐Orbital Occupancy Enables High Photocatalytic H₂ Evolution

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(25)

Published: April 25, 2023

The interaction between a co-catalyst and photocatalyst usually induces spontaneous free-electron transfer them, but the effect regulation of direction on hydrogen-adsorption energy active sites have not received attention. Herein, to steer in favorable for weakening S-Hads bonds sulfur-rich MoS2+x , an electron-reversal strategy is proposed first time. core-shell Au@MoS2+x cocatalyst was constructed TiO2 optimize antibonding-orbital occupancy. Research results reveal that embedded Au can reverse electron generate electron-rich S(2+δ)- sites, thus increasing occupancy cocatalyst. Consequently, increase effectively destabilizes H 1s-p antibonding orbital weakens bond, realizing expedited desorption Hads rapidly lot visible H2 bubbles. This work delves deep into latent carrier cocatalytic activity.

Language: Английский

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Directional and Ultrafast Charge Transfer in Oxygen‐Vacancy‐Rich ZnO@Single‐Atom Cobalt Core‐Shell Junction for Photo‐Fenton‐Like Reaction

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(30)

Published: May 31, 2023

In photosynthesis, solar energy is harvested by photosensitizers, and then, the excited electrons transfer via a Z-Scheme mode to enzymatic catalytic centers trigger redox reactions. Herein, we constructed core-shell Z-scheme heterojunction of semiconductor@single-atom catalysts (SACs). The oxygen-vacancy-rich ZnO core single-atom Co-N4 sites supported on nitrogen-rich carbon shell (SA-Co-CN) act as photosensitizer enzyme-mimicking active centers, respectively. Driven built-in electric field across heterojunction, photoexcited could rapidly (2 ps) from n-type p-type SA-Co-CN shell, finally boosting performance surface-exposed for peroxymonosulfate (PMS) activation under light irradiation. synergies between photocatalysis heterogeneous Fenton-like reaction lead phenomenally enhanced production various reactive oxygen species rapid degradation microcontaminants in water. Experimental theoretical results validate that interfacial coupling with greatly facilitates PMS adsorption reducing enhancing cascade electron processes photo-Fenton-like reaction.

Language: Английский

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Optimization of the IO3 polar group of BiOIO3 by bulk phase doping amplifies pyroelectric polarization to enhance carrier separation and improve the pyro-photo-electric catalytic performance

Applied Catalysis B Environment and Energy, Journal Year: 2023, Volume and Issue: 339, P. 123169 - 123169

Published: Aug. 13, 2023

Language: Английский

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Directional and Ultrafast Charge Transfer in Oxygen‐Vacancy‐Rich ZnO@Single‐Atom Cobalt Core‐Shell Junction for Photo‐Fenton‐Like Reaction

Angewandte Chemie, Journal Year: 2023, Volume and Issue: 135(30)

Published: May 31, 2023

Abstract In photosynthesis, solar energy is harvested by photosensitizers, and then, the excited electrons transfer via a Z‐Scheme mode to enzymatic catalytic centers trigger redox reactions. Herein, we constructed core–shell Z‐scheme heterojunction of semiconductor@single‐atom catalysts (SACs). The oxygen‐vacancy‐rich ZnO core single‐atom Co−N 4 sites supported on nitrogen‐rich carbon shell (SA‐Co‐CN) act as photosensitizer enzyme‐mimicking active centers, respectively. Driven built‐in electric field across heterojunction, photoexcited could rapidly (2 ps) from n ‐type p SA‐Co‐CN shell, finally boosting performance surface‐exposed for peroxymonosulfate (PMS) activation under light irradiation. synergies between photocatalysis heterogeneous Fenton‐like reaction lead phenomenally enhanced production various reactive oxygen species rapid degradation microcontaminants in water. Experimental theoretical results validate that interfacial coupling with greatly facilitates PMS adsorption reducing enhancing cascade electron processes photo‐Fenton‐like reaction.

Language: Английский

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Custom‐Design of Strong Electron/Proton Extractor on COFs for Efficient Photocatalytic H₂O₂ Production

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(15)

Published: Feb. 14, 2024

The development of photocatalysts with continuous electron extraction and rapid proton transfer could kinetically accelerate the artificial photosynthesis, but remains a challenge. Herein, we report topology-guided synthesis high-crystalline triazine covalent organic framework (COF) decorated by uniformly distributed polar oxygen functional groups (sulfonic group or carboxyl) as strong electron/proton extractor for efficient photocatalytic H

Language: Английский

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Photocoupled Electroreduction of CO₂ over Photosensitizer-Decorated Covalent Organic Frameworks

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(36), P. 19856 - 19865

Published: Aug. 31, 2023

Introducing an external visible-light field would be a promising strategy to improve the activity of electrocatalytic CO2 reduction reaction (CO2RR), but it still remains challenge due short excited-state lifetime active sites. Herein, Ru(bpy)3Cl2 struts as powerful photosensitive donors were immobilized into backbones Co-porphyrin-based covalent organic frameworks (named Co-Bpy-COF-Rux, x is molar ratio Ru and Co species, = 1/2 2/3) via coordination bonds, for photo-coupled CO2RR produce CO. The optimal Co-Bpy-COF-Ru1/2 displays high CO Faradaic efficiency 96.7% at -0.7 V vs reversible hydrogen electrode (RHE) partial current density 16.27 mA cm-2 -1.1 RHE under assistance light, both which far surpassing values observed in dark. significantly enhanced mainly attributed incorporation donor with long concomitantly giant built-in electric Co-Bpy-COF-Ru1/2, efficiently accelerate photo-induced electron transfer from cobalt-porphyrin light. Thus, sites have longer lower rate-determining steps' energy occurring during actual process. This first work porphyrin-based COFs CO2RR, opening new frontier construction efficient electrocatalysts.

Language: Английский

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Ultrathin covalent organic framework nanosheets for enhanced photocatalytic water oxidation

Science Advances, Journal Year: 2024, Volume and Issue: 10(3)

Published: Jan. 17, 2024

Photocatalytic water oxidation is a key half-reaction for various solar-to-fuel conversion systems but requires simultaneous affinity and hole accumulation at the photocatalytic site. Here, we present rational design synthesis of an ionic-type covalent organic framework (COF) named tetraphenylporphyrin cobalt bipyridine complex (CoTPP-CoBpy 3 ) COF, combining porphyrin building blocks as photocatalyst oxidation. The good dispersibility porous large-size (>2 micrometers) COF nanosheets (≈1.45 nanometers) facilitates local collection; ultrafast triplet-state charge transfer (1.8 picoseconds) prolonged separation (1.2 nanoseconds) further contribute to efficient holes in CoTPP moiety, leading dioxygen production rate 7323 micromoles per gram hour. Moreover, have identified end-on superoxide radical (O 2 · intermediate active site moiety proposed electron-intermediate cascade mechanism that elucidates synergistic coupling electron relay (S 1 -T ′) evolution during process.

Language: Английский

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Enhancing Built‐in Electric Fields via Molecular Symmetry Modulation in Supramolecular Photocatalysts for Highly Efficient Photocatalytic Hydrogen Evolution

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(26)

Published: April 22, 2024

Nature-inspired supramolecular self-assemblies are attractive photocatalysts, but their quantum yields limited by poor charge separation and transportation. A promising strategy for efficient transfer is to enhance the built-in electric field symmetry breaking. Herein, an unsymmetric protonation, N-heterocyclic π-conjugated anthrazoline-based photocatalyst SA-DADK-H

Language: Английский

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Integrating Uranyl-Affinity “Hooks” into Conjugated Polymers Achieving Giant Built-in Electric Field for Boosting Photocatalytic Uranium Extraction from Seawater

Macromolecules, Journal Year: 2024, Volume and Issue: 57(12), P. 5679 - 5690

Published: June 10, 2024

Language: Английский

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