Weakly Hydrophilic Imine-Linked Covalent Benzene–Acetylene Frameworks for Photocatalytic H₂O₂ Production in the Two-Phase System

ACS Applied Materials & Interfaces, Год журнала: 2023, Номер 15(6), С. 8066 - 8075

Опубликована: Фев. 1, 2023

Conversing oxygen (O2) to hydrogen peroxide (H2O2) driven by solar energy is a promising H2O2 onsite production route but often short of efficient and durable photocatalysts. Herein, strong π-π conjugate polycyclic aromatic benzene acetylene units have been constructed into new covalent organic frameworks (COFs) linked imine C═N bonding. These COFs demonstrated two-dimensional hexagonal crystalline with higher crystallinity larger surface area (>600 m2 g-1). Covalent benzene-acetylene possessed appropriate visible light-responsive band structure the suppressed charge recombination rate. The -OH groups on their enable them be weakly hydrophilic. As result, it served as high-performance photocatalysts for in water-benzyl alcohol (BA) two-phase system. It delivered rate 1240 μmol h-1 gcat-1 catalytic efficiency within 60 h, comparable best COF-based catalysts. This study provides an photocatalytic system based hydrophilic imine-linked

Язык: Английский

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Fully Conjugated 2D sp² Carbon‐Linked Covalent Organic Frameworks for Photocatalytic Overall Water Splitting

Advanced Materials, Год журнала: 2023, Номер 36(6)

Опубликована: Окт. 11, 2023

Abstract Covalent organic frameworks (COFs) hold great promise for solar‐driven hydrogen production. However, metal‐free COFs photocatalytic overall water splitting remain elusive, primarily due to challenges in simultaneously regulating their band structures and catalytic sites enable concurrent half‐reactions. Herein, two types of π‐conjugated containing the same donor–acceptor structure are constructed via Knoevenagel condensation Schiff base reaction afford cyanovinylene‐ imine‐bridged COFs, respectively. The difference linkage leads a remarkable activity toward splitting. 2D sp 2 carbon‐linked COF exhibits notable splitting, which can reach an apparent quantum efficiency 2.53% at 420 nm. In contrast, imine‐linked cannot catalyze water‐splitting reaction. Mechanistic investigations reveal that cyanovinylene is essential modulating promoting charge separation thereby enabling Moreover, it further shown crystallinity substantially impacts performance COFs. This study represents first successful example developing with high

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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Molecular‐Level Regulation Strategies Toward Efficient Charge Separation in Donor−Acceptor Type Conjugated Polymers for Boosted Energy‐Related Photocatalysis

Advanced Energy Materials, Год журнала: 2023, Номер 14(5)

Опубликована: Дек. 11, 2023

Abstract The development of efficient photocatalysts for artificial photocatalytic energy conversion is an intriguing strategy. Promisingly, conjugated polymers (CPs) have been actively investigated as alternatives to traditional inorganic semiconductors photocatalysis due their molecularly tunable optoelectronic properties, thus providing a great platform molecular design. Incorporating donor (D) and acceptor (A) units into the backbone CPs ensures adequate D−A interface, which essential facilitating charge separation. This approach also allows bandgaps leading significant progress in conversions recent years. Here, fundamentals D–A type are initially outlined, followed by advanced experimental methods density functional theory (DFT) calculations investigating carrier dynamics. Then, detailed exposition synthetic strategies carried out. Their extensive applications diverse energy‐related conversions, such hydrogen evolution, oxygen overall water splitting, CO 2 reduction, N H O evolution comprehensively presented. review provides new comprehensive insights molecular‐level design catalysts boosted conversion, expected further advance photocatalysis.

Язык: Английский

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Molecular Engineering for Modulating Photocatalytic Hydrogen Evolution of Fully Conjugated 3D Covalent Organic Frameworks

Angewandte Chemie International Edition, Год журнала: 2024, Номер 63(25)

Опубликована: Апрель 16, 2024

Covalent organic frameworks (COFs) have recently shown great potential for photocatalytic hydrogen production. Currently almost all reports are focused on two-dimensional (2D) COFs, while the 3D counterparts rarely explored due to their non-conjugated derived from sp

Язык: Английский

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