Structural Motifs in Covalent Organic Frameworks for Photocatalysis

Advanced Functional Materials, Год журнала: 2024, Номер unknown

Опубликована: Март 10, 2024

Abstract Covalent organic frameworks (COFs) attract significant attention due to their ordered, crystalline, porous, metal‐free, and predictable structures. These unique characteristics offer great opportunities for the diffusion transmission of photogenerated charges during photocatalysis. Currently, a considerable number COFs are used as metal‐free semiconductor photocatalysts. This review aims understand relationships between structure photocatalysis performance provides in‐depth insight into synthetic strategy improve performance. Subsequently, focuses on structural motif in sustainable photocatalytic hydrogen evolution, carbon dioxide reduction, peroxide generation, compound transformations. Last, conjunction with progress achieved challenges yet be overcome, candid discussion is undertaken regarding field COF photocatalysis, accompanied by presentation potential research avenues future directions. seeks provide readers comprehensive understanding pivotal role robust guidance innovative utilization

Язык: Английский

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Boosting CO₂ Photoreduction via Regulating Charge Transfer Ability in a One‐Dimensional Covalent Organic Framework

Angewandte Chemie International Edition, Год журнала: 2023, Номер 62(46)

Опубликована: Сен. 28, 2023

Two-dimensional (2D) imine-based covalent organic frameworks (COFs) hold potential for photocatalytic CO2 reduction. However, high energy barrier of imine linkage impede the in-plane photoelectron transfer process, resulting in inadequate efficiency photoreduction. Herein, we present a dimensionality induced local electronic modulation strategy through construction one-dimensional (1D) pyrene-based (PyTTA-COF). The dual-chain-like edge architectures 1D PyTTA-COF enable stabilization aromatic backbones, thus reducing loss during exciton dissociation and thermal relaxation, which provides energetic to traverse linkages. As result, exhibits significantly enhanced photoreduction activity under visible-light irradiation when coordinated with metal cobalt ion, yielding remarkable CO evolution 1003 μmol g-1 over an 8-hour period, surpasses that corresponding 2D counterpart by factor 59. These findings valuable approach address charge limitations COFs.

Язык: Английский

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

Advanced Materials, Год журнала: 2023, Номер 36(1)

Опубликована: Окт. 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

Язык: Английский

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Catalytic Linkage Engineering of Covalent Organic Frameworks for the Oxygen Reduction Reaction

Angewandte Chemie International Edition, Год журнала: 2023, Номер 62(30)

Опубликована: Апрель 28, 2023

Metal-free covalent organic frameworks (COFs) have been employed to catalyze the oxygen reduction reaction (ORR). To achieve high activity and selectivity, various building blocks containing heteroatoms groups linked by imine bonds were used create catalytic COFs. However, roles of linkages COFs in ORR not investigated. In this work, linkage engineering has modulate behaviors. single sites while avoiding other possible sites, we synthesized from benzene units bonds, such as imine, amide, azine, oxazole bonds. Among these COFs, oxazole-linkage enables with highest activity, which achieved a half-wave potential 0.75 V limited current density 5.5 mA cm-2 . Moreover, oxazole-linked COF conversion frequency (TOF) value 0.0133 S-1 , 1.9, 1.3, 7.4-times that azine-, amide- imine-COFs, respectively. The theoretical calculation showed carbon atoms facilitated formation OOH* promoted protonation O* form OH*, thus advancing activity. This work guides us on are suitable for ORR.

Язык: Английский

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Postsynthetic Annulation of Three-Dimensional Covalent Organic Frameworks for Boosting CO₂ Photoreduction

Journal of the American Chemical Society, Год журнала: 2023, Номер 145(28), С. 15473 - 15481

Опубликована: Июль 8, 2023

Three-dimensional covalent organic frameworks (3D COFs), with interconnected pores and exposed functional groups, provide new opportunities for the design of advanced materials through postsynthetic modification. Herein, we demonstrate successful annulation 3D COFs to construct efficient CO2 reduction photocatalysts. Two COFs, NJU-318 NJU-319Fe, were initially constructed by connecting hexaphenyl-triphenylene units pyrene- or Fe-porphyrin-based linkers. Subsequently, moieties within postsynthetically transformed into π-conjugated hexabenzo-trinaphthylene (pNJU-318 pNJU-319Fe) enhance visible light absorption photoreduction activity. The optimized photocatalyst, pNJU-319Fe, shows a CO yield 688 μmol g-1, representing 2.5-fold increase compared that unmodified NJU-319Fe. Notably, direct synthesis hexabenzo-trinaphthylene-based COF catalysts was unsuccessful due low solubility conjugated This study not only provides an effective method photocatalysts but also highlights unlimited tunability structural

Язык: Английский

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Construction of a novel metal-free heterostructure photocatalyst PRGO/TP-COF for enhanced photocatalytic CO2 reduction

Applied Catalysis B Environment and Energy, Год журнала: 2024, Номер 350, С. 123937 - 123937

Опубликована: Апрель 24, 2024

Язык: Английский

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Positional Thiophene Isomerization: A Geometric Strategy for Precisely Regulating the Electronic State of Covalent Organic Frameworks to Boost Oxygen Reduction

Angewandte Chemie International Edition, Год журнала: 2024, Номер 63(15)

Опубликована: Фев. 13, 2024

Abstract With the oxygen conversion efficiency of metal‐free carbon‐based fuel cells dramatically improved, building blocks covalent organic frameworks (COFs) raised principal concerns on catalytic active sites with indistinct electronic states. Herein, to address this issue, we demonstrate COFs for reduction reaction (ORR) by regulating edge‐hanging thiophene units, and molecular geometries are further modulated via positional isomerization strategy, affording isomeric COF‐α 2‐substitution COF‐β 3‐substitution frameworks. The states intermediate adsorption ability well‐regulated through geometric modification, resulting in controllable chemical activity local density π‐electrons. Notably, introduction units different substitution positions into a pristine pure COF model COF‐Ph achieves excellent half‐wave potential 0.76 V versus reversible hydrogen electrode, which is higher than most those or metal‐based electrocatalysts. Utilizing combination theoretical prediction situ Raman spectra, show that skeleton ( ) can induce dangling unit activation, accurately identifying pentacyclic‐carbon (thiophene α‐position) adjacent sulfur atom as sites. results suggest groups suitable ORR promising geometry construction.

Язык: Английский

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Engineering of a hierarchical S-scheme 2D/3D heterojunction with graphdiyne (g-C_nH_2n−2) coated 3D porous CoAl₂O₄ nanoflowers for highly efficient photocatalytic H₂ evolution

Journal of Materials Chemistry A, Год журнала: 2024, Номер 12(14), С. 8543 - 8560

Опубликована: Янв. 1, 2024

In this work, a novel 2D/3D hierarchical architecture graphdiyne/CoAl 2 O 4 (GCA) S-scheme heterojunction was successfully constructed by coupling graphdiyne (GDY) nanosheets onto porous CoAl nanoflowers.

Язык: Английский

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Construction of COF/COF Organic S‐Scheme Heterostructure for Enhanced Overall Water Splitting

Advanced Materials, Год журнала: 2024, Номер unknown

Опубликована: Окт. 18, 2024

Covalent organic frameworks (COFs) as a new type of photocatalysts have shown unique advantages in visible-light-driven hydrogen evolution, while the reported overall water-splitting systems are still very rare among various COF-based photocatalysts. Herein, two COFs integrated to construct S-scheme heterojunction for improved water splitting. In this system, TpBpy-COF and COF-316 serve H

Язык: Английский

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Stepwise Protonation of Three‐Dimensional Covalent Organic Frameworks for Enhancing Hydrogen Peroxide Photosynthesis

Angewandte Chemie International Edition, Год журнала: 2024, Номер 63(30)

Опубликована: Май 13, 2024

Abstract Three‐dimensional covalent organic frameworks (3D COFs), recognized for their tailorable structures and accessible active sites, offer a promising platform developing advanced photocatalysts. However, the difficulty in synthesis functionalization of 3D COFs hinders further development. In this study, we present series 3D‐ bcu ‐COFs with 8 connected porphyrin units linked by linear linkers through imine bonds as versatile photocatalyst design. The photoresponse was initially modulated functionalizing benzo‐thiadiazole or benzo‐selenadiazole groups. Furthermore, taking advantage well‐exposed sites ‐COFs, photocatalytic activity optimized stepwise protonation centers. dual protonated COF groups exhibited enhanced charge separation, leading to an increased H 2 O production under visible light. This enhancement demonstrates combined benefits linker on efficiency.

Язык: Английский

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