Construction of 2D S‐Scheme Heterojunction Photocatalyst

Advanced Materials, Год журнала: 2023, Номер 36(8)

Опубликована: Ноя. 22, 2023

Abstract Semiconductor photocatalytic technology holds immense promise for converting sustainable solar energy into chemically storable energy, with significant applications in the realms of and environment. However, inherent issue rapid recombination photogenerated electrons holes hinders performance single photocatalysts. To overcome this challenge, construction 2D S‐scheme heterojunction photocatalysts emerges as an effective strategy. The deliberate design dimensionality ensures a substantial interfacial area; while, charge transfer mechanism facilitates efficient separation maximizes redox capabilities. This review commences fresh perspective on heterojunctions, followed by comprehensive exploration preparation methods characterization techniques. Subsequently, recent advancements are summarized. Notably, behind activity enhancement is elucidated. Finally, prospects development presented.

Язык: Английский

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Challenges of Z-scheme photocatalytic mechanisms

Trends in Chemistry, Год журнала: 2022, Номер 4(11), С. 973 - 983

Опубликована: Сен. 16, 2022

Язык: Английский

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Sulfone‐Modified Covalent Organic Frameworks Enabling Efficient Photocatalytic Hydrogen Peroxide Generation via One‐Step Two‐Electron O₂ Reduction

Angewandte Chemie International Edition, Год журнала: 2023, Номер 62(26)

Опубликована: Апрель 25, 2023

Abstract Photocatalytic oxygen reduction reaction (ORR) offers a promising hydrogen peroxide (H 2 O ) synthetic strategy, especially the one‐step two‐electron (2e − ORR route holds great potential in achieving highly efficient and selectivity. However, 2e is rarely harvested underlying mechanism for regulating pathways remains greatly obscure. Here, by loading sulfone units into covalent organic frameworks (FS‐COFs), we present an photocatalyst H generation via from pure water air. Under visible light irradiation, FS‐COFs exert superb yield of 3904.2 μmol h −1 g , outperforming most reported metal‐free catalysts under similar conditions. Experimental theoretical investigation reveals that accelerate separation photoinduced electron‐hole (e ‐h + pairs, enhance protonation COFs, promote adsorption Yeager‐type, which jointly alters process two‐step to one, thereby with high

Язык: Английский

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Solar‐to‐H₂O₂ Catalyzed by Covalent Organic Frameworks

Angewandte Chemie International Edition, Год журнала: 2023, Номер 62(49)

Опубликована: Авг. 14, 2023

Abstract Benefiting from the excellent structural tunability, robust framework, ultrahigh porosity, and rich active sites, covalent organic frameworks (COFs) are widely recognized as promising photocatalysts in chemical conversions, emerged hydrogen peroxide (H 2 O ) photosynthesis 2020. H , serving an environmental‐friendly oxidant a liquid fuel, has attracted increasing researchers to explore its potential. Over past few years, numerous COFs‐based developed with encouraging achievements production, whereas no comprehensive review articles exist summarize this specific significant area. Herein we provide systematic overview of advances challenges COFs photocatalytic production. We first introduce priorities photosynthesis. Then, various strategies improve efficiency discussed. The perspective outlook for future emerging field finally offered. This timely will pave way development highly efficient practical production value‐added chemicals not limited .

Язык: 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, Год журнала: 2023, Номер 145(38), С. 20837 - 20848

Опубликована: Авг. 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.

Язык: Английский

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Covalent organic frameworks for direct photosynthesis of hydrogen peroxide from water, air and sunlight

Nature Communications, Год журнала: 2023, Номер 14(1)

Опубликована: Июль 19, 2023

Solar-driven photosynthesis is a sustainable process for the production of hydrogen peroxide, efficiency which plagued by side reactions. Metal-free covalent organic frameworks (COFs) that can form suitable intermediates and inhibit reactions show great promise to photo-synthesize H2O2. However, insufficient formation separation/transfer photogenerated charges in such materials restricts H2O2 production. Herein, we provide strategy design donor-acceptor COFs greatly boost photosynthesis. We demonstrate optimal intramolecular polarity COFs, achieved using amounts phenyl groups as electron donors, maximize free charge generation, leads high yield rates (605 μmol g-1 h-1) from water, oxygen visible light without sacrificial agents. Combining in-situ characterization with computational calculations, describe how triazine N-sites N 2p states play crucial role H2O activation selective oxidation into further experimentally be efficiently produced tap, river or sea water natural sunlight air decontamination.

Язык: Английский

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Interfacial Chemical Bond and Oxygen Vacancy‐Enhanced In₂O₃/CdSe‐DETA S‐scheme Heterojunction for Photocatalytic CO₂ Conversion

Advanced Functional Materials, Год журнала: 2023, Номер 33(23)

Опубликована: Март 2, 2023

Abstract The S‐scheme heterojunctions have great potential for photocatalytic carbon dioxide reduction due to their unique carrier migration pathways, superior separation efficiencies, and high redox capacities. However, the precise process of oriented powerful electron transport remains a challenge. Herein, an InOCd bond‐modulated heterojunction In 2 O 3 /CdSe‐DETA is synthesized by simple microwave‐assisted hydrothermal method accelerated photogenerated transfer. Meanwhile, oxygen vacancies (Vo) capture effect. Consequently, thanks synergistic effect this In‐Vo‐In‐O‐Cd structural units at interface, electrons are extracted rapidly transferred surface‐active sites, which improves electronic coupling CO . This finding precisely adjusts transfer pathway shortens distance. chemical bond established in heterostructure with (Vo‐In ) provides new insights into reduction.

Язык: Английский

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Bifunctional TiO2/COF S-scheme photocatalyst with enhanced H2O2 production and furoic acid synthesis mechanism

Applied Catalysis B Environment and Energy, Год журнала: 2023, Номер 333, С. 122780 - 122780

Опубликована: Апрель 25, 2023

Язык: Английский

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In Situ Synthesis of Chemically Bonded 2D/2D Covalent Organic Frameworks/O‐Vacancy WO₃ Z‐Scheme Heterostructure for Photocatalytic Overall Water Splitting

Advanced Materials, Год журнала: 2023, Номер 35(33)

Опубликована: Июнь 15, 2023

Abstract Covalent organic frameworks (COFs) have shown great promise for photocatalytic hydrogen evolution via water splitting. However, the four‐electron oxidation of remains elusive toward oxygen evolution. Enabling this pathway is critical to improve yield and maximize atom utilization efficiency. A Z‐scheme heterojunction proposed overcoming fundamental issues in COF‐based overall splitting (OWS), such as inefficient light absorption, charge recombination, poor ability. It that construction a novel 2D/2D through situ growth COFs on O‐vacancy WO 3 nanosheets (Ov‐WO ) WOC chemical bond can remarkably promote OWS. Benefiting from synergistic effect between enhanced built‐in electric field by interfacial bond, strong ability Ov‐WO 3, ultrathin structure TSCOF, both separation efficiency photogenerated electron–hole pairs be significantly enhanced. An impressive half‐rection rate 593 mmol h −1 g 146 (hydrogen) 68 (oxygen) µmol are achieved COF‐WO (TSCOFW) composite. This with two‐step excitation precisely cascaded charge‐transfer makes it responsible efficient solar‐driven OWS without sacrificial agent.

Язык: Английский

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Enhancing photocatalytic H2O2 production with Au co-catalysts through electronic structure modification

Nature Communications, Год журнала: 2024, Номер 15(1)

Опубликована: Апрель 13, 2024

Abstract Gold-based co-catalysts are a promising class of materials with potential applications in photocatalytic H 2 O production. However, current approaches Au show limited production due to intrinsically weak adsorption at the site. We report an approach strengthen sites, and improve production, through formation electron-deficient δ+ sites by modifying electronic structure. In this case, we synthesis TiO /MoS x -Au, following selective deposition onto MoS surface which is then further anchored . that catalyst achieves significantly increased rate 30.44 mmol g −1 h -saturated solution containing ethanol. Density functional theory calculations X-ray photoelectron spectroscopy analysis reveal mediator induces thereby decreasing antibonding-orbital occupancy Au-O ads subsequently enhancing adsorption. This strategy may be useful for rationally designing structure surfaces facilitate artificial photosynthesis.

Язык: Английский

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