Iodide‐Induced Fragmentation of Polymerized Hydrophilic Carbon Nitride for High‐Performance Quasi‐Homogeneous Photocatalytic H₂O₂ Production

Angewandte Chemie International Edition, Journal Year: 2021, Volume and Issue: 60(48), P. 25546 - 25550

Published: Sept. 18, 2021

Polymeric carbon nitride (PCN) as a class of two-electron oxygen reduction reaction (2 e- ORR) photocatalyst has attracted much attention for H2 O2 production. However, the low activity and inferior selectivity 2 ORR greatly restrict production efficiency. Herein, we develop new strategy to synthesize hydrophilic, fragmented PCN by terminating polymerization (TP-PCN) effect iodide ions. The obtained TP-PCN with abundant edge active sites (AEASs), which can form quasi-homogeneous photocatalytic system, exhibits superior generation rate (3265.4 μM h-1 ), far surpassing other PCN-based photocatalysts. DFT calculations further indicate that is more favorable electron transiting from β spin-orbital π* orbitals , optimizes activation reduces energy barrier formation. This work provides concept designing functional photocatalysts understanding mechanism in

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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A Crystalline Carbon Nitride Based Near‐Infrared Active Photocatalyst

Advanced Functional Materials, Journal Year: 2022, Volume and Issue: 32(47)

Published: Sept. 16, 2022

Abstract Efficient utilization of near‐infrared (NIR) light that takes a primary percentage the solar spectrum is great significance for practical applications photocatalysis. However, development singular NIR‐based photocatalysts still remains grand challenge. Herein, crystalline carbon nitride photocatalyst proposed by using molten‐salt assisted protocol with carbohydrazide as oxygen‐containing precursor. Different from doping strategy always leads to structural damage and crystallinity decrease, oxygen arising special precursor itself introduced into framework C 3 N 4 highly structure formed. The n→π* excitation therefore activated absorption edge extended remarkably 1400 nm. Theoretical calculations also reveal local internal electric field simultaneously generated promoting charge separation/migration kinetics. Benefiting incorporation formation, synthesized material shows significantly enhanced visible‐light (λ > 420 nm) hydrogen production reactivity compared benchmark nitride, more importantly an active NIR generation 700 long‐wavelength overall water splitting = 600 capability rarely reported photocatalysts. This study showcases illustration promising efficient fuel production.

Language: Английский

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Defective polymeric carbon nitride: Fabrications, photocatalytic applications and perspectives

Chemical Engineering Journal, Journal Year: 2021, Volume and Issue: 427, P. 130991 - 130991

Published: June 25, 2021

Language: Английский

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Plasmonic Nanozyme of Graphdiyne Nanowalls Wrapped Hollow Copper Sulfide Nanocubes for Rapid Bacteria‐Killing

Advanced Functional Materials, Journal Year: 2022, Volume and Issue: 32(20)

Published: Feb. 9, 2022

Abstract Plasmon stimulation represents an appealing way to modulate enzyme mimic functions, but utilization efficiency of plasmon excitation remains relatively low. To overcome this drawback, a heterojunction composite based on graphdiyne nanowalls wrapped hollow copper sulfide nanocubes (CuS@GDY) with strong localized surface resonance (LSPR) response in the near‐infrared (NIR) region is developed. This nanozyme can concurrently harvest LSPR induced hot carriers and produce photothermal effects, resulting dramatically increased peroxidase‐like activity when exposed 808 nm light. Both experimental results theoretical calculations show that remarkable catalytic performance CuS@GDY due unique hierarchical structure, narrow bandgap GDY nanowalls, effect CuS nanocages, fast interfacial electron transfer dynamics, carbon vacancies CuS@GDY. plasmonic exhibits rapid, efficient, broad‐spectrum antibacterial ( > 99.999%) against diverse pathogens (methicillin‐resistant Staphylococcus aureus , Escherichia coli ). study not only sheds light mechanism nanozyme‐/photocatalysis coupling process, also opens up new avenue for engineering NIR driven nanozymes rapid synergistic photo‐enhanced therapy.

Language: Английский

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Interlayer Palladium-Single-Atom-Coordinated Cyano-Group-Rich Graphitic Carbon Nitride for Enhanced Photocatalytic Hydrogen Production Performance

ACS Catalysis, Journal Year: 2022, Volume and Issue: 12(9), P. 5077 - 5093

Published: April 14, 2022

To improve the photocatalytic hydrogen evolution activity of palladium-assisted graphitic carbon nitride (g-C3N4), here, palladium-single-atom-coordinated cyano-group-rich g-C3N4 (Pd/DN-UCN) are synthesized, and synthesis process includes copolymerization urea-derived supramolecular aggregates NH4Cl followed by wet impregnation. By combining powerful characteristic results theoretical calculations, formation mechanism Pd single atoms on ultrathin, mesoporous nanosheets is proposed, highlighting that firmly stabilized in interlayers caused combination physical confinement effect coordination bonding cyano groups with atoms; additionally, Pd–N3 Pd/DN-UCN heterojunctions confirmed, which one atom coordinates N group two sp2-hybridized adjacent layer. The presence Pd–N induces a midgap state band structure g-C3N4. At optimal loading levels (0.16%), synthesized 0.16%Pd/DN-UCN0.50 exhibits enhanced production as compared to electrostatically "sixfold cavities" g-C3N4, apparent quantum yield values at stationary point concentration (1.2 g L–1) can reach up 14.6, 15.8, 4.69, 3.05% under monochromatic light irradiation 365, 400, 450, 550 nm, respectively. cooperation significantly boosted transfer photoexcited electrons atomically dispersed sites via as-built interlayer delivery channels maximal utilization efficiency dominates Pd/DN-UCN.

Language: Английский

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Ultrathin porous carbon nitride nanosheets with well-tuned band structures via carbon vacancies and oxygen doping for significantly boosting H2 production

Applied Catalysis B Environment and Energy, Journal Year: 2022, Volume and Issue: 314, P. 121521 - 121521

Published: May 16, 2022

Language: Английский

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Construction of rGO-coupled C3N4/C3N5 2D/2D Z-scheme heterojunction to accelerate charge separation for efficient visible light H2 evolution

Applied Catalysis B Environment and Energy, Journal Year: 2022, Volume and Issue: 318, P. 121822 - 121822

Published: Aug. 4, 2022

Language: Английский

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Multifunctional carbon nitride nanoarchitectures for catalysis

Chemical Society Reviews, Journal Year: 2023, Volume and Issue: 52(21), P. 7602 - 7664

Published: Jan. 1, 2023

Carbon nitrides, with feasibility of tailored band gap via suitable nanoarchitectonics, are deemed as best catalysts amongst existing materials, especially for HER, OWS, COR, NRR, water oxidation, pollutant removal, and organocatalysis.

Language: Английский

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Intramolecular D-A structure and n-π* transition co-promoted photodegradation activity of carbon nitride: Performance, mechanism and toxicity insight

Chemical Engineering Journal, Journal Year: 2022, Volume and Issue: 456, P. 141029 - 141029

Published: Dec. 17, 2022

Language: Английский

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