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

Advanced Functional Materials, Год журнала: 2023, Номер 34(1)

Опубликована: Сен. 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

Язык: Английский

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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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New Advances in Covalent Network Polymers via Dynamic Covalent Chemistry

Chemical Reviews, Год журнала: 2024, Номер 124(12), С. 7829 - 7906

Опубликована: Июнь 3, 2024

Covalent network polymers, as materials composed of atoms interconnected by covalent bonds in a continuous network, are known for their thermal and chemical stability. Over the past two decades, these have undergone significant transformations, gaining properties such malleability, environmental responsiveness, recyclability, crystallinity, customizable porosity, enabled development integration dynamic chemistry (DCvC). In this review, we explore innovative realm polymers focusing on recent advances achieved through application DCvC. We start examining history fundamental principles DCvC, detailing its inception core concepts noting key role reversible bond formation. Then reprocessability DCvC is thoroughly discussed, starting from milestones that marked evolution progressing to current trends applications. The influence crystallinity then reviewed, covering diversity, synthesis techniques, functionalities. concluding section, address challenges faced field speculates potential future directions.

Язык: Английский

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Hierarchical assembly of donor–acceptor covalent organic frameworks for photosynthesis of hydrogen peroxide from water and air

Nature Synthesis, Год журнала: 2024, Номер 3(8), С. 998 - 1010

Опубликована: Май 17, 2024

Язык: Английский

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Regulating the H₂O₂ Photosynthetic Activity of Covalent Organic Frameworks through Linkage Orientation

ACS Catalysis, Год журнала: 2024, Номер 14(7), С. 4728 - 4737

Опубликована: Март 13, 2024

Imine-linked isomeric covalent organic frameworks (COFs) with opposite linkage orientations are not rare, but their structure and photocatalytic property corrections still puzzling, let alone the emerging photosynthetic H2O2 performance. Herein, a pair of COFs (TB-COF TA-COF) reversed imine linkages was fabricated. Compared to TA-COF, TB-COF exhibited larger dipole moments better charge carrier separation efficiency, resulting in superior photosynthesis capability via dominant oxygen reduction reaction (ORR) paths (O2–O2•––H2O2 O2–O2•––O21–H2O2) feeble water oxidation (WOR) paths. With no sacrificial agents air, rates were 5186 μmol g–1 h–1 4111 natural seawater, respectively. The seawater-produced can be directly utilized for tetracycline degradation, manifesting big picture wastewater treatment by H2O2. Theoretical calculations revealed that hydroxyl-rich benzene ring photooxidation part triazine unit primary photoreduction part. Through linkage-orientation regulation, electronic structures, migration property, energy barrier rate determination step 2e– ORR WOR well-modulated. current work provides insight into effect orientation on performance may enlighten design catalysts photosynthesis.

Язык: Английский

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Flexible Units Induced Three-Dimensional Covalent Organic Frameworks with a Heteromotif Molecular Junction for Photocatalytic H₂O₂ Production

ACS Catalysis, Год журнала: 2024, Номер 14(6), С. 3778 - 3787

Опубликована: Фев. 22, 2024

In recent years, significant progress has been achieved in the field of three-dimensional covalent organic frameworks (3D COFs). However, there is still a great challenge to use flexible building units synthesize high-connectivity 3D COFs. this work, we showed that [6 + 3] COFs could be constructed by inducing highly planar blocks from C3 antitriangular prismed blocks. Herein, two with spn topology based on cyclotriphosphazene were and denoted as TAA/TAB-CTP-COF, their redox ability photophysical features can finely regulated coupled functional group, such benzene triazine groups. As result, heteromotif molecular junction TAA-CTP-COF fully exposed active sites high photocatalytic production hydrogen peroxide (H2O2) yield 1041 μM h–1 without any additional photosensitizers, scavengers, or cocatalysts. Furthermore, presence an electron donor, rate H2O2 reach up 2221 h–1, exhibiting one best performances for crystalline materials. This work showcases potential using highlights versatility efficacy metal-free solar energy conversion.

Язык: Английский

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Unlocking Synthesis of Polyhedral Oligomeric Silsesquioxane-Based Three-Dimensional Polycubane Covalent Organic Frameworks

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(5), С. 3373 - 3382

Опубликована: Янв. 25, 2024

Reticular chemistry effectively yields porous structures with distinct topological lattices for a broad range of applications. Polyhedral oligomeric silsesquioxane (POSS)-based octatopic building blocks rare Oh symmetric configuration and attracting inorganic features have great potential creating three-dimensional (3D) covalent organic frameworks (COFs) new topologies. However, the intrinsic flexibility intensive motion cubane-type POSS molecules make construction 3D regular challenging. Herein, by fastening three or four cores per aromatic rigid linker from rational steric directions, we successfully developed serial crystalline COFs unpresented "the" scu Both experimental theoretical results proved formation target POSS-based COFs. The resultant hybrid networks designable chemical skeletons high surface areas maintain superiorities both components, such as their compatibility salts, abundant periodic electroactive sites, excellent thermal stability, open multilevel nanochannels. Consequently, polycubane could serve outstanding solid electrolytes ionic conductivity 1.23 × 10–4 S cm–1 lithium-ion transference number 0.86 at room temperature. This work offers pathway to generate ordered multiconnected flexible cube motifs enrich topologies

Язык: Английский

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1D Covalent Organic Frameworks Triggering Highly Efficient Photosynthesis of H₂O₂ via Controllable Modular Design

Angewandte Chemie International Edition, Год журнала: 2024, Номер 63(12)

Опубликована: Фев. 1, 2024

The topological diversity of covalent organic frameworks (COFs) enables considerable space for exploring their structure-performance relationships. In this study, we report a sequence novel 1D COFs (EO, ES, and ESe-COF) with typical 4-c sql topology that can be interconnected VIA group elements (O, S, Se) via modular design strategy. It is found the electronic structures, charge delivery property, light harvesting ability, hydrophilicity these profoundly influenced by bridge-linked atom ordinal. Finally, EO-COF, possessing highest quantity active sites, longest lifetime electron, strongest interaction O

Язык: Английский

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A 3D Phosphorescent Supramolecular Organic Framework in Aqueous Solution

Advanced Functional Materials, Год журнала: 2024, Номер 34(25)

Опубликована: Фев. 4, 2024

Abstract Supramolecular organic framework (SOF) has recently garnered significant research interest in the field of luminescent materials. However, SOF with room‐temperature phosphorescence emission solution is very rare due to quenching dissolved oxygen and free molecular motions, which would lead nonradiative deactivation triplet exciton liquid state. In this work, a 3D cationic phosphorescent synthesized through host‐guest interaction between CB[8] tetrahedral monomer TBBP, can rapidly adsorb anionic guests solution. When dyes are introduced, singlet Förster resonance energy transfer (TS‐FRET) be achieved, delayed fluorescence large Stokes shift realized. Additionally, when drugs TBBP‐CB[8] quenched charge transfer, enabling detection signals. Taking advantage fast adsorption property SOF, an INHIBIT logic gate three inputs two outputs constructed. These findings provide novel method prepare functional materials new pathway construct TS‐FRET system

Язык: Английский

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Thiazole-linked isomeric covalent organic frameworks for divergent photocatalysis: Selective oxidation of organic sulfides

Applied Catalysis B Environment and Energy, Год журнала: 2024, Номер 354, С. 124103 - 124103

Опубликована: Апрель 21, 2024

Язык: Английский

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