Reconstructed covalent organic frameworks

Nature, Journal Year: 2022, Volume and Issue: 604(7904), P. 72 - 79

Published: April 6, 2022

Abstract Covalent organic frameworks (COFs) are distinguished from other polymers by their crystallinity 1–3 , but it remains challenging to obtain robust, highly crystalline COFs because the framework-forming reactions poorly reversible 4,5 . More chemistry can improve 6–9 this typically yields with poor physicochemical stability and limited application scope 5 Here we report a general scalable protocol prepare imine COFs, based on an unexpected framework reconstruction. In contrast standard approaches in which monomers initially randomly aligned, our method involves pre-organization of using removable covalent tether, followed confined polymerization. This reconstruction route produces reconstructed greatly enhanced much higher porosity means simple vacuum-free synthetic procedure. The increased improves charge carrier transport, leading sacrificial photocatalytic hydrogen evolution rates up 27.98 mmol h −1 g nanoconfinement-assisted strategy is step towards programming function materials through atomistic structural control.

Language: Английский

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Linking oxidative and reductive clusters to prepare crystalline porous catalysts for photocatalytic CO2 reduction with H2O

Nature Communications, Journal Year: 2022, Volume and Issue: 13(1)

Published: Aug. 10, 2022

Mimicking natural photosynthesis to convert CO2 with H2O into value-added fuels achieving overall reaction is a promising way reduce the atmospheric level. Casting catalyst of two or more catalytic sites rapid electron transfer and interaction may be an effective strategy for coupling photocatalytic reduction oxidation. Herein, based on MOF ∪ COF collaboration, we have carefully designed synthesized crystalline hetero-metallic cluster denoted MCOF-Ti6Cu3 spatial separation functional cooperation between oxidative reductive clusters. It utilizes dynamic covalent bonds clusters promote photo-induced charge efficiency, drive both reactions. exhibits fine activity in conversion water HCOOH (169.8 μmol g-1h-1). Remarkably, experiments theoretical calculations reveal that photo-excited electrons are transferred from Ti Cu, indicating Cu center.

Language: Английский

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Two-Dimensional Covalent Organic Frameworks with Cobalt(II)-Phthalocyanine Sites for Efficient Electrocatalytic Carbon Dioxide Reduction

Journal of the American Chemical Society, Journal Year: 2021, Volume and Issue: 143(18), P. 7104 - 7113

Published: May 3, 2021

The rapid development in synthesis methodology and applications for covalent organic frameworks (COFs) has been witnessed recent years. However, the of highly stable functional COFs still remains a great challenge. Herein two-dimensional polyimide-linked phthalocyanine (denoted as CoPc-PI-COF-1 CoPc-PI-COF-2) have devised prepared through solvothermal reaction tetraanhydrides 2,3,9,10,16,17,23,24-octacarboxyphthalocyaninato cobalt(II) with 1,4-phenylenediamine 4,4′-biphenyldiamine, respectively. resultant CoPc-PI-COFs four-connected sql net exhibit AA stacking configurations according to powder X-ray diffraction studies, showing permanent porosity, thermal stability above 300 °C, excellent resistance 12 M HCl aqueous solution 20 days. Current–voltage curves reveal conductivity CoPc-PI-COF-2 value 3.7 × 10–3 1.6 S m–1, Due same Co(II) electroactive sites together similar porosity CO2 adsorption capacity CoPc-PI-COFs, cathodes made up carbon black display CO2-to-CO Faradaic efficiency 87–97% at applied potentials between −0.60 −0.90 V (vs RHE) 0.5 KHCO3 solution. comparison CoPc-PI-COF-2&carbon electrode, counterpart provides larger current density (jCO) −21.2 mA cm–2 associated its higher conductivity. This cathode also high turnover number frequency, amounting 277 000 2.2 s–1 −0.70 during 40 h measurement. present result clearly discloses potential 2D porous crystalline solids electrocatalysis.

Language: Английский

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Nanostructured metal phosphides: from controllable synthesis to sustainable catalysis

Chemical Society Reviews, Journal Year: 2021, Volume and Issue: 50(13), P. 7539 - 7586

Published: Jan. 1, 2021

Metal phosphides (MPs) with unique and desirable physicochemical properties provide promising potential in implementable sustainable catalytic fields including electrocatalysis, photocatalysis, mild thermocatalysis, interdisciplinary hybrid systems.

Language: Английский

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Integration of metal-organic frameworks and covalent organic frameworks: Design, synthesis, and applications

Matter, Journal Year: 2021, Volume and Issue: 4(7), P. 2230 - 2265

Published: July 1, 2021

Language: Английский

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Nanoscale covalent organic frameworks: from controlled synthesis to cancer therapy

Chemical Communications, Journal Year: 2021, Volume and Issue: 57(93), P. 12417 - 12435

Published: Jan. 1, 2021

The controlled synthesis methods and the applications of nanoscale covalent organic frameworks in cancer therapy are summarized this feature article.

Language: Английский

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Computation-based regulation of excitonic effects in donor-acceptor covalent organic frameworks for enhanced photocatalysis

Nature Communications, Journal Year: 2023, Volume and Issue: 14(1)

Published: May 29, 2023

The strong excitonic effects widely exist in polymer-semiconductors and the large exciton binding energy (Eb) seriously limits their photocatalysis. Herein, density functional theory (DFT) calculations are conducted to assess band alignment charge transfer feature of potential donor-acceptor (D-A) covalent organic frameworks (COFs), using 1,3,5-tris(4-aminophenyl)triazine (TAPT) or 1,3,5-tris(4-aminophenyl)benzene (TAPB) as acceptors tereph-thaldehydes functionalized diverse groups donors. Given discernable D-A interaction strengths pairs, Eb can be systematically regulated with minimum TAPT-OMe. Guided by these results, corresponding COFs synthesized, where TAPT-OMe-COF possesses best activity photocatalytic H2 production trend other is associated that calculated for pairs. In addition, further alkyne cycloaddition imine linkage greatly improves stability resulting TAPT-OMe-alkyne-COF a substantially smaller exhibits ~20 times higher than parent COF.

Language: Английский

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Metalated covalent organic frameworks: from synthetic strategies to diverse applications

Chemical Society Reviews, Journal Year: 2022, Volume and Issue: 51(15), P. 6307 - 6416

Published: Jan. 1, 2022

This review highlights the recent advances of metalated covalent organic frameworks, including synthetic strategies and applications, discusses current challenges future directions.

Language: Английский

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Photocatalytic CO2 conversion over single-atom MoN2 sites of covalent organic framework

Applied Catalysis B Environment and Energy, Journal Year: 2021, Volume and Issue: 291, P. 120146 - 120146

Published: March 18, 2021

Language: Английский

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Intramolecular hydroxyl nucleophilic attack pathway by a polymeric water oxidation catalyst with single cobalt sites

Nature Catalysis, Journal Year: 2022, Volume and Issue: 5(5), P. 414 - 429

Published: May 25, 2022

Abstract Exploration of efficient water oxidation catalysts (WOCs) is the primary challenge in conversion renewable energy into fuels. Here we report a molecularly well-defined heterogeneous WOC with Aza-fused, π-conjugated, microporous polymer (Aza-CMP) coordinated single cobalt sites (Aza-CMP-Co). The Aza-CMP-Co exhibited superior activity under alkaline and near-neutral conditions. Moreover, molecular nature isolated catalytic makes reliable model for studying mechanism. By combination experimental theoretical results, pH-dependent nucleophilic attack pathway O-O bond formation was proposed. Under conditions, intramolecular hydroxyl (IHNA) process which adjacent -OH group nucleophilically attacks Co 4+ =O identified as rate-determining step. This leads to lower activation accelerated kinetics than those intermolecular (WNA) pathway. study provides significant insights crucial function electrolyte pH catalysis enhancement by regulation IHNA

Language: Английский

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