Halogen-functionalized covalent organic frameworks for photocatalytic Cr(VI) reduction under visible light

Journal of Hazardous Materials, Год журнала: 2024, Номер 476, С. 134956 - 134956

Опубликована: Июнь 21, 2024

Язык: Английский

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Controlling crystallization in covalent organic frameworks to facilitate photocatalytic hydrogen production

Nature Communications, Год журнала: 2025, Номер 16(1)

Опубликована: Фев. 24, 2025

Abstract The catalytic performance, depending on the surface nature, is ubiquitous in photocatalysis. However, engineering for organic photocatalysts through structural modulation has long been neglected. Here, we propose a zone crystallization strategy covalent frameworks (COFs) that enhances ordering regulator-induced amorphous-to-crystalline transformation. Dynamic simulations show attaching monofunctional regulators to of spherical amorphous precursor improves dynamic reversibility, increasing crystallinity from inside out. resulting COF microspheres display surface-enhanced and uniform morphology. visible photocatalytic hydrogen evolution rate reaches 126 mmol g –1 h simplest β-ketoenamine-linked 350 SiO 2 @COF with minimal Pt cocatalysts. Mechanism studies indicate crystalline domains build electrical fields accumulate photogenerated electrons diminish electron transfer barriers between interface. This work bridges gap microscopic molecules macroscopic properties, allowing tailored design photocatalysts.

Язык: Английский

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Photons, Excitons, and Electrons in Covalent Organic Frameworks

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(47), С. 32161 - 32205

Опубликована: Ноя. 18, 2024

Covalent organic frameworks (COFs) are created by the condensation of molecular building blocks and nodes to form two-dimensional (2D) or three-dimensional (3D) crystalline frameworks. The diversity with different properties functionalities large number possible framework topologies open a vast space well-defined porous architectures. Besides more classical applications materials such as absorption, separation, catalytic conversions, interest in optoelectronic COFs has recently increased considerably. electronic both their linkage chemistry can be controlled tune photon absorption emission, create excitons charge carriers, use these carriers photocatalysis, luminescence, chemical sensing, photovoltaics. In this Perspective, we will discuss relationship between structural features properties, starting connectivity, layer stacking 2D COFs, control over defects morphology including thin film synthesis, exploring theoretical modeling structural, electronic, dynamic discussing recent intriguing focus on photocatalysis photoelectrochemistry. We conclude some remarks about present challenges future prospects powerful architectural paradigm.

Язык: Английский

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Reticular Materials for Photocatalysis

Advanced Materials, Год журнала: 2024, Номер unknown

Опубликована: Ноя. 27, 2024

Abstract Photocatalysis leverages solar energy to overcome the thermodynamic barrier, enabling efficient chemical reactions under mild conditions. It can greatly reduce reliance on traditional sources and has attracted significant research interest. Reticular materials, including metal‐organic frameworks (MOFs) covalent organic (COFs), represent a class of crystalline materials constructed from molecular building blocks linked by coordination bonds, respectively. function as heterogeneous catalysts, combining well‐defined structures high tailorability akin homogeneous catalysts. In this review, regulation light absorption, charge separation, surface in photocatalytic process through precise molecular‐level design based features reticular is elaborated. Notably, for MOFsmicroenvironment modulation around catalytic sites affects performance delved, with emphasis their unique dynamic flexible microenvironments. For COFs, inherent excitonic effects due fully nature discussed highlight strategies regulate charge‐ and/or energy‐transfer‐mediated photocatalysis. Finally, current challenges future directions field, aiming provide comprehensive understanding how be optimized enhanced photocatalysis discussed.

Язык: Английский

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Porphyrin-based covalent organic frameworks from design, synthesis to biological applications

Biomaterials Science, Год журнала: 2024, Номер 12(11), С. 2766 - 2785

Опубликована: Янв. 1, 2024

Covalent organic frameworks (COFs) constitute a class of highly functional porous materials composed lightweight elements interconnected by covalent bonds, characterized structural order, high crystallinity, and large specific surface area.

Язык: Английский

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Probing Defects in Covalent Organic Frameworks

ACS Applied Materials & Interfaces, Год журнала: 2024, Номер 16(38), С. 50096 - 50114

Опубликована: Сен. 16, 2024

Defects in covalent organic frameworks (COFs) play a pivotal role determining their properties and performance, significantly influencing interactions with adsorbates, guest molecules, substrates as well affecting charge carrier dynamics light absorption characteristics. The present review focuses on the diverse array of techniques employed for characterizing quantifying defects COFs, addressing critical need field materials science. As will be discussed this review, there are basically two types referring either to missing moieties leaving free binding groups material or structural imperfections resulting lower crystallinity, grain boundary defects, incomplete stacking. summarizes an in-depth analysis state-of-the-art characterization techniques, elucidating specific strengths limitations each defect type. Key examined include powder X-ray diffraction (PXRD), infrared spectroscopy (IR), thermogravimetric (TGA), nuclear magnetic resonance (NMR), photoelectron (XPS), scanning electron microscope (SEM), transmission microscopy (STEM), tunneling (STM), high resolution microcoe (HRTEM), gas adsorption, acid-base titration, advanced methods, computational calculations. We critically assess capability technique provide qualitative quantitative information about COF offering insights into complementary nature potential synergistic use. last section main concepts provides perspectives future development overcome existing challenges.

Язык: Английский

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Linkage Engineering of Semiconductive Covalent‐Organic Frameworks toward Room‐Temperature Ppb‐Level Selective Ammonia Sensing

Small, Год журнала: 2025, Номер unknown

Опубликована: Фев. 16, 2025

Rational design of molecular architectures is crucial for developing advanced materials such as covalent-organic frameworks (COFs) with excellent sensing performance. In this work, two isostructural COFs (β-keto-AnCOF and imine-AnCOF) the same conjugated linkers but distinct linkages are constructed. Although both have porous structure semiconductor behavior conferred by identical backbones, β-keto-AnCOF ─C═O side groups exhibits superior room-temperature ammonia (NH3) performance than imine-AnCOF even state-of-the-art dynamic commercial NH3 sensors, i.e., high sensitivity up to 18.94% ppm-1, ultralow experimental detection limit 1 ppb, outstanding selectivity, remarkable response stability reproducibility after 180 days. situ spectroscopy theoretical calculation reveal that additional charge transfer between sites in effectively increases distance Fermi level valence band, enabling highly-sensitive at ppb levels. This work provides novel next-generation high-performance sensors.

Язык: Английский

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Advancements in Understanding the Physicochemical Properties of Reticular Materials: An In Situ and Operando Spectroscopic Perspective

Advanced Materials, Год журнала: 2025, Номер unknown

Опубликована: Фев. 24, 2025

The application of in situ and operando spectroscopic techniques has significantly advanced the understanding reticular materials, particularly metal-organic frameworks (MOFs) covalent organic (COFs). These offer real-time insights into dynamic structural, electronic, chemical changes that occur within these materials during various processes, such as catalysis, sorption, material synthesis. This review offers a comprehensive overview key used to investigate formation, functionalization, catalytic behavior materials. How have elucidated roles active sites, reaction intermediates, structural transformations under conditions, especially single-site electrocatalysis, photocatalysis, is highlighted. also discusses challenges opportunities lie ahead integrating methods with aiming foster further innovation design versatile

Язык: Английский

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Adsorption of cationic organic dyes from aqueous solutions by sulfonated covalent organic frameworks: Characterization and mechanistic explanations

Separation and Purification Technology, Год журнала: 2025, Номер unknown, С. 132466 - 132466

Опубликована: Март 1, 2025

Язык: Английский

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10% Conversion of Imine into Thiazole in Covalent Organic Frameworks for Efficient Photocatalytic H₂O₂ Generation

Advanced Functional Materials, Год журнала: 2025, Номер unknown

Опубликована: Март 17, 2025

Abstract The 5–10 nm exciton diffusion distance for most organic semiconductors is much less than the particle size of 2D covalent frameworks (COFs). As a result, local structure change in small domain COFs, rather whole particles, could effectively promote charge transfer photocatalysis. Herein, three‐component condensation used to preparing four mixed imine‐ and thiazole‐linked donor‐acceptor (D–A) COFs. In contrast 100% imine ca. 90% 10% materials have 77–95% higher photocatalytic hydrogen peroxide (H 2 O ) production rate pure water due more prolonged lifetime excitation state. particular, USTB‐10‐S exhibits H generation 5041 µmol g −1 h . Coupling with benzyl alcohol as sacrificial reagent, its further increased 16152 , superior COF‐based photocatalysts. This work illustrates proof‐of‐concept that COFs tiny amount able significantly enhance separation thus performance, inspiring development defect engineering field

Язык: Английский

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