Covalent organic frameworks for photocatalysis: Synthesis, structural features, fundamentals and performance

Coordination Chemistry Reviews, Journal Year: 2022, Volume and Issue: 475, P. 214889 - 214889

Published: Oct. 15, 2022

Language: Английский

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Covalent Organic Framework Based Functional Materials: Important Catalysts for Efficient CO₂Utilization

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 61(15)

Published: Jan. 21, 2022

As hot topics in the chemical conversion of CO2 , photo-/electrocatalytic reduction and use as a supporter for energy storage have shown great potential utilization . However, many obstacles still exist on road to realizing highly efficient conversion, such inefficient uptake/activation mass transport catalysts. Covalent organic frameworks (COFs), kind porous material, been widely explored catalysts owing their unique features. In particular, COF-based functional materials containing diverse active sites (such single metal sites, nanoparticles, oxides) offer storage. This Minireview discusses recent breakthroughs basic knowledge, mechanisms, pathways strategies that addition, challenges prospects are also introduced.

Language: Английский

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Shear Stress Triggers Ultrathin-Nanosheet Carbon Nitride Assembly for Photocatalytic H₂O₂ Production Coupled with Selective Alcohol Oxidation

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(38), P. 20837 - 20848

Published: Aug. 25, 2023

Coupled photocatalysis without cocatalysts can maximize the utilization of photons and atoms, which puts forward higher demands on photocatalysts. Polymeric carbon nitride (CN) has become most promising photocatalyst, but still suffers from major drawbacks insufficient catalytic sites low quantum efficiency. Herein, we report a fluid shear stress-assisted molecular assembly to prepare ultrathin-nanosheet-assembled acanthosphere-like CN (ASCN) with nitrogen vacancy (Nv) carbonyl modification. Shear stress breaks stacking interactions between layers cuts stacked structure into ultrathin layers, are further reassembled acanthosphere bundles driven by "centrifugal force". Benefitted greatly nature that provides more exposed active improves charge carrier separation, ASCN-3 exhibits 20-fold activity than bulk counterpart toward oxygen reduction H2O2 coupled 4-methoxybenzyl alcohol (4-MBA) oxidation anisaldehyde (AA), significantly increased turnover frequency (TOF) values (TOF: 1.69 h–1 for 1.02 AA). Significantly, 95.8% conversion 4-MBA nearly 100% selectivity. High apparent yields 11.7% 9.3% at 420 nm achieved photosynthesis oxidation. Mechanism studies suggest induces holes concentrated neighboring melem unit directly oxidize Cα–H bond produce radicals, Nv as adsorption site traps electrons form superoxide radical combines shed protons H2O2. This work presents simple physical method break layered stack creating hierarchical photocatalysis.

Language: Английский

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Covalent Organic Frameworks for Energy Conversion in Photocatalysis

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(34)

Published: April 24, 2023

Abstract Intensifying energy crises and severe environmental issues have led to the discovery of renewable sources, sustainable conversion, storage technologies. Photocatalysis is a green technology that converts eco‐friendly solar into high‐energy chemicals. Covalent organic frameworks (COFs) are porous materials constructed by covalent bonds show promising potential for converting chemicals owing their pre‐designable structures, high crystallinity, porosity. Herein, we highlight recent progress in synthesis COF‐based photocatalysts applications water splitting, CO 2 reduction, H O production. The challenges future opportunities rational design COFs advanced discussed. This Review expected promote further development toward photocatalysis.

Language: Английский

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Three-Dimensional Covalent Organic Frameworks with Ultra-Large Pores for Highly Efficient Photocatalysis

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(5), P. 3248 - 3254

Published: Jan. 31, 2023

Benefiting from their unique structural merits, three-dimensional (3D) large-pore COF materials demonstrate high surface areas and interconnected large channels, which makes these promising in practical applications. Unfortunately, functionalization strategies application research are still absent structures. To this end, a series of functional 3D stp-topologized COFs designed based on porphyrin or metalloporphyrin moieties, named JUC-640-M (M = Co, Ni, H). Interestingly, JUC-640-H exhibits record-breaking low crystal density (0.106 cm3 g-1) among all crystalline materials, along with the largest pore size (4.6 nm) COFs, area (2204 m2 g-1), abundant exposed moieties (0.845 mmol g-1). Inspired by characteristics photoelectrical performance, JUC-640-Co is utilized for photoreduction CO2 to CO demonstrates production rate (15.1 g-1 h-1), selectivity (94.4%), stability. It should be noted that has exceeded those reported COF-based materials. This work not only produces novel channels but also provides new guidance applications COFs.

Language: Английский

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Covalent organic frameworks towards photocatalytic applications: Design principles, achievements, and opportunities

Coordination Chemistry Reviews, Journal Year: 2022, Volume and Issue: 475, P. 214882 - 214882

Published: Oct. 14, 2022

Language: Английский

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Transformation of Porous Organic Cages and Covalent Organic Frameworks with Efficient Iodine Vapor Capture Performance

Journal of the American Chemical Society, Journal Year: 2022, Volume and Issue: 144(27), P. 12390 - 12399

Published: June 29, 2022

The reaction of 5,5′-([2,2′-bipyridine]-5,5′-diyl)diisophthalaldehyde (BPDDP) with cyclohexanediamine and [benzidine (BZ)/[2,2′-bipyridine]-5,5′-diamine (BPDA)], respectively, affords a nitrogen-rich porous organic cage BPPOC two two-dimensional (2D) covalent frameworks (COFs), USTB-1 USTB-2 (USTB = University Science Technology Beijing), under suitable conditions. Interestingly, single-crystal X-ray diffraction structure is able to successfully transform into (newly converted COFs denoted as USTB-1c USTB-2c, respectively) upon exchange the imine unit in by BZ BPDA. Such transformation also enables isolation analogous (USTB-3c USTB-4c) on basis an isostructural cage, BTPOC, which derived from 5,5′-([2,2′-bithiophene]-4,4′-diyl)diisophthalaldehyde (BTDDP) cyclohexanediamine. However, conventional solvothermal between BTDDP BPDA leads impure phase USTB-4 containing incompletely aldehyde groups due limited solubility building block. newly prepared have been characterized nuclear magnetic resonance spectroscopy, Fourier infrared scanning electron microscopy, transmission microscopy. In particular, absorb iodine vapor uptake 5.64 g g–1, breaking cage's (POC's) record value 3.78 g–1. Nevertheless, cage-derived exhibit improved adsorption capability comparison directly synthesized counterparts, highest 5.80 g–1 for USTB-1c. mechanism investigation unveils superiority nitrogen atoms sulfur POCs capture assistance definite crystal structures. This, combination porosity, synergistically influences capacity COFs.

Language: Английский

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Ingenious Artificial Leaf Based on Covalent Organic Framework Membranes for Boosting CO₂ Photoreduction

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(17), P. 9520 - 9529

Published: April 19, 2023

Covalent organic frameworks (COFs) hold the potential in converting CO2 with water into value-added fuels and O2 to save deteriorating ecological environment. However, reaching high yield selectivity is a grand challenge under metal-, photosensitizer-, or sacrificial reagent-free conditions. Here, inspired by microstructures of natural leaves, we designed triazine-based COF membranes integration steady light-harvesting sites, efficient catalytic center, fast charge/mass transfer configuration fabricate novel artificial leaf for first time. Significantly, record CO 1240 μmol g–1 4 h reaction, approximately 100% selectivity, long lifespan (at least 16 cycles) were achieved gas–solid conditions without using any metal, photosensitizer, reagent. Unlike existing knowledge, chemical structural unit triazine-imide-triazine unique physical form membrane are predominant such remarkable photocatalysis. This work opens new pathway simulating photosynthesis leaves may motivate relevant research future.

Language: Английский

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Photocatalytic CO2 reduction using La-Ni bimetallic sites within a covalent organic framework

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

Published: April 29, 2023

The precise construction of photocatalysts with diatomic sites that simultaneously foster light absorption and catalytic activity is a formidable challenge, as both processes follow distinct pathways. Herein, an electrostatically driven self-assembly approach used, where phenanthroline used to synthesize bifunctional LaNi within covalent organic framework. La Ni site acts optically catalytically active center for photocarriers generation highly selective CO2-to-CO reduction, respectively. Theory calculations in-situ characterization reveal the directional charge transfer between La-Ni double-atomic sites, leading decreased reaction energy barriers *COOH intermediate enhanced conversion. As result, without any additional photosensitizers, 15.2 times enhancement CO2 reduction rate (605.8 μmol·g-1·h-1) over benchmark framework colloid (39.9 improved CO selectivity (98.2%) are achieved. This work presents potential strategy integrating centers enhance photocatalytic reduction.

Language: Английский

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Integrating Dual-Metal Sites into Covalent Organic Frameworks for Enhanced Photocatalytic CO₂ Reduction

ACS Catalysis, Journal Year: 2023, Volume and Issue: 13(7), P. 4316 - 4329

Published: March 15, 2023

Photocatalytic CO2 reduction holds great promise for synchronously addressing carbon neutrality and producing fuels, although enhancing the photocatalyst activity tuning product selectivity remain enormous challenges. Herein, we synthesized four crystalline porous benzothiadiazole-based covalent organic frameworks (COFs) with different carbonyl groups reported a dual metalation strategy to fabricate Co Ni dual-metal sites anchored on COFs by interaction between metal thiadiazole high-performance photoreduction. Among as-synthesized metalated Co/Ni sites, CoNi–COF-3 achieved an impressive CO generation rate of 2567 μmol g–1 h–1 92.2%, which were significantly higher than those single sites. Experimental theoretical results revealed that superior photocatalytic performance was attributed synergic effect fully β-ketoenamine-tautomerized COF-3 configuration not only facilitated photogenerated charge carrier dynamics but also reduced energy barriers *COOH formation promoted adsorption desorption. This work provides valuable insights into future design improved COF photocatalysts conversion.

Language: Английский

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