Machine learning-guided realization of full-color high-quantum-yield carbon quantum dots

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

Опубликована: Июнь 6, 2024

Abstract Carbon quantum dots (CQDs) have versatile applications in luminescence, whereas identifying optimal synthesis conditions has been challenging due to numerous parameters and multiple desired outcomes, creating an enormous search space. In this study, we present a novel multi-objective optimization strategy utilizing machine learning (ML) algorithm intelligently guide the hydrothermal of CQDs. Our closed-loop approach learns from limited sparse data, greatly reducing research cycle surpassing traditional trial-and-error methods. Moreover, it also reveals intricate links between target properties unifies objective function optimize like full-color photoluminescence (PL) wavelength high PL yields (PLQY). With only 63 experiments, achieve fluorescent CQDs with PLQY exceeding 60% across all colors. study represents significant advancement ML-guided synthesis, setting stage for developing new materials properties.

Язык: Английский

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High Quantum Yield Amino Acid Carbon Quantum Dots with Unparalleled Refractive Index

ACS Nano, Год журнала: 2024, Номер 18(3), С. 2421 - 2433

Опубликована: Янв. 8, 2024

Carbon quantum dots (CQDs) are one of the most promising types fluorescent nanomaterials due to their exceptional water solubility, excellent optical properties, biocompatibility, chemical inertness, refractive index, and photostability. Nitrogen-containing CQDs, which include amino acid based especially attractive high yield, thermal stability, potential biomedical applications. Recent studies have attempted improve preparation CQDs. However, highest yield obtained for these was only 44%. Furthermore, indices derived CQDs were not determined. Here, we systematically explored performance prepared from all 20 coded acids using modified hydrothermal techniques allowing more passivation layers on surface optimize performance. Intriguingly, ever reported any The values differed among acids, with found positively charged including arginine-CQDs (∼2.1), histidine-CQDs (∼2.0), lysine-CQDs (∼1.8). here showed a nearly 2-fold increase in (∼86%) longer decay time (∼8.0 ns) compared previous reports. In addition, also demonstrated that CQD materials displayed excitation-dependent emission profiles (from UV visible) photostable, water-soluble, noncytotoxic, contrast live cell imaging or bioimaging. These results indicate high-refractive-index applicable optoelectronic devices, bioimaging, biosensing, studying cellular organelles vivo. This extraordinary RI may be highly useful exploring elements different densities.

Язык: Английский

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Boosting the photosynthesis of hydrogen peroxide directly from pure water and air over S-scheme fiber heterojunction

Science China Materials, Год журнала: 2024, Номер 67(2), С. 484 - 492

Опубликована: Янв. 12, 2024

Язык: Английский

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Protonated g-C3N4/oxygen-doped g-C3N4 S-scheme homojunction fabricated by electrostatic self-assembly for photocatalytic hydrogen evolution and tetracycline hydrochloride degradation

Carbon, Год журнала: 2024, Номер 226, С. 119153 - 119153

Опубликована: Апрель 18, 2024

Язык: Английский

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Amide‐Engineered Metal–Organic Porous Liquids Toward Enhanced CO₂ Photoreduction Performance

Advanced Functional Materials, Год журнала: 2024, Номер 34(19)

Опубликована: Янв. 17, 2024

Abstract The development of alternative catalytic systems toward high‐performance CO 2 photoreduction is considered to be a promising approach address the future energy demand and reduce emissions. However, molecules are thermodynamically stable in nature, thus adsorption activation on surface catalysts key factors determine conversion efficiency. Herein, porous liquid (NH ‐UIO‐66 PL) demonstrated for efficiently facilitating by modification metal–organic framework ‐UIO‐66) with ionic via amide bonds. CdS/NH PL exhibits ‐to‐CO yield 71.37 µmol g −1 h selectivity 100%. Experiments theoretical calculations show that introduced moieties not only enriched electron density at Zr 4+ active sites but also stabilize * COOH intermediate. achievements provide an effective strategy frameworks catalysis.

Язык: Английский

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Nitrogen‐Rich Carbon Dot‐Mediated n→π* Electronic Transition in Carbon Nitride for Superior Photocatalytic Hydrogen Peroxide Production

Advanced Functional Materials, Год журнала: 2024, Номер 34(38)

Опубликована: Май 7, 2024

Abstract Solar‐driven synthesis of hydrogen peroxide (H 2 O ) through photocatalysis stands out as a promising avenue for sustainable energy generation, marked by environmental friendliness and industrial feasibility. However, the inherent limitations carbon nitride (CN) in photocatalytic H production significantly impede their performance. Herein, novel 0D/2D dots‐modified CN nanosheet heterojunction (CDsMCN) is introduced, synthesized hydrothermal‐calcination tandem strategy induced CDs derived from melamine. This innovative technique enhances n→π* electronic transition CDsMCN, accelerating separation efficiency electron‐hole pairs, boosting oxygen adsorption, promoting highly selective 2e − ORR. Comparative to pristine CN, 10 MCN exhibited remarkable tenfold increase production, reaching an impressive 1.48 mmol L −1 . Furthermore, demonstrates exceptional stability, maintaining its catalytic at initial level over four consecutive cycles. The notable achievement molar selectivity ≈80% onset potential 0.6 V (vs RHE) underscores ability produce desired product selectively. Advanced situ characterization together with DFT calculations revealed that ultrathin enhanced improves optical properties, reduces bandgap, facilitates fast charge migration, increases performance, thereby serving candidate advanced applications.

Язык: Английский

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Phosphorescent carbon dots: Intermolecular interactions, properties, and applications

Coordination Chemistry Reviews, Год журнала: 2024, Номер 503, С. 215642 - 215642

Опубликована: Янв. 2, 2024

Язык: Английский

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Isomerization Engineering of Oxygen‐Enriched Carbon Quantum Dots for Efficient Electrochemical Hydrogen Peroxide Production

Small, Год журнала: 2024, Номер unknown

Опубликована: Май 7, 2024

Abstract Hydrogen peroxide (H 2 O ) has emerged as a kind of multi‐functional green oxidants with extensive industrial utility. Oxidized carbon materials exhibit promises electrocatalysts in the two‐electron (2e − oxygen reduction reaction (ORR) for H production. However, precise identification and fabrication active sites that selectively yield present serious challenge. Herein, structural engineering strategy is employed to synthesize oxygen‐doped quantum dots (o‐CQD) 2e ORR. The surface electronic structure o‐CQDs systematically modulated by varying isomerization precursors, thereby demonstrating excellent electrocatalyst performance. Notably, o‐CQD‐3 emerges most promising candidate, showcasing remarkable selectivity 96.2% (n = 2.07) at 0.68 V versus RHE, coupled low Tafel diagram 66.95 mV dec −1 . In flow cell configuration, achieves productivity 338.7 mmol g catalyst h , maintaining consistent production stability over an impressive 120‐hour duration. Utilizing situ technology density functional theory calculations, it unveil edge are facilely functionalized C‐O‐C groups under alkaline ORR conditions. This approach advances forefront sustainable catalysis provides profound insight into carbon‐based design environmental‐friendly chemical synthesis processes.

Язык: Английский

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Engineering Built‐In Electric Field Microenvironment of CQDs/g‐C₃N₄ Heterojunction for Efficient Photocatalytic CO₂ Reduction

Advanced Science, Год журнала: 2024, Номер 11(28)

Опубликована: Май 10, 2024

Abstract Graphitic carbon nitride (CN), as a nonmetallic photocatalyst, has gained considerable attention for its cost‐effectiveness and environmentally friendly nature in catalyzing solar‐driven CO 2 conversion into valuable products. However, the photocatalytic efficiency of reduction with CN remains low, accompanied by challenges achieving desirable product selectivity. To address these limitations, two‐step hydrothermal‐calcination tandem synthesis strategy is presented, introducing quantum dots (CQDs) forming ultra‐thin CQD/CN nanosheets. The integration CQDs induces distinct work function CN, creating robust interface electric field after combination. This facilitates accumulation photoelectrons region, providing an abundant source reduced electrons process. Remarkably, nanosheets exhibit average yield 120 µmol g −1 , showcasing outstanding selectivity 92.8%. discovery not only presents innovative pathway development high‐performance photocatalysts grounded non‐metallic materials employing but also opens new avenues versatile application prospects environmental protection sustainable cleaning energy.

Язык: Английский

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Unveiling the synergistic role of nitrogen vacancies and Z-scheme heterojunction in g-C3N4/β-Bi2O3 hybrids for enhanced CO2 photoreduction

Nano Energy, Год журнала: 2024, Номер 124, С. 109494 - 109494

Опубликована: Март 13, 2024

Язык: Английский

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