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1.
J Am Chem Soc ; 146(26): 17866-17877, 2024 Jul 03.
Artículo en Inglés | MEDLINE | ID: mdl-38916547

RESUMEN

Construction of mesoporous frameworks by noncovalent bonding still remains a great challenge. Here, we report a micelle-directed nanocluster modular self-assembly approach to synthesize a novel type of two-dimensional (2-D) hydrogen-bonded mesoporous frameworks (HMFs) for the first time based on nanoscale cluster units (1.0-3.0 nm in size). In this 2-D structure, a mesoporous cluster plate with ∼100 nm in thickness and several micrometers in size can be stably formed into uniform hexagonal arrays. Meanwhile, such a porous plate consists of several (3-4) dozens of layers of ultrathin mesoporous cluster nanosheets. The size of the mesopores can be precisely controlled from 11.6 to 18.5 nm by utilizing the amphiphilic diblock copolymer micelles with tunable block lengths. Additionally, the pore configuration of the HMFs can be changed from spherical to cylindrical by manipulating the concentration of the micelles. As a general approach, various new HMFs have been achieved successfully via a modular self-assembly of nanoclusters with switchable configurations (nanoring, Keggin-type, and cubane-like) and components (titanium-oxo, polyoxometalate, and organometallic clusters). As a demonstration, the titanium-oxo cluster-based HMFs show efficient photocatalytic activity for hydrogen evolution (3.6 mmol g-1h-1), with a conversion rate about 2 times higher than that of the unassembled titanium-oxo clusters (1.5 mmol g-1h-1). This demonstrates that HMFs exhibited enhanced photocatalytic activity compared with unassembled titanium-oxo clusters units.

2.
Angew Chem Int Ed Engl ; 63(23): e202403245, 2024 Jun 03.
Artículo en Inglés | MEDLINE | ID: mdl-38578838

RESUMEN

The encapsulation of functional colloidal nanoparticles (100 nm) into single-crystalline ZSM-5 zeolites, aiming to create uniform core-shell structures, is a highly sought-after yet formidable objective due to significant lattice mismatch and distinct crystallization properties. In this study, we demonstrate the fabrication of a core-shell structured single-crystal zeolite encompassing an Fe3O4 colloidal core via a novel confinement stepwise crystallization methodology. By engineering a confined nanocavity, anchoring nucleation sites, and executing stepwise crystallization, we have successfully encapsulated colloidal nanoparticles (CN) within single-crystal zeolites. These grafted sites, alongside the controlled crystallization process, compel the zeolite seed to nucleate and expand along the Fe3O4 colloidal nanoparticle surface, within a meticulously defined volume (1.5×107≤V≤1.3×108 nm3). Our strategy exhibits versatility and adaptability to an array of zeolites, including but not restricted to ZSM-5, NaA, ZSM-11, and TS-1 with polycrystalline zeolite shell. We highlight the uniformly structured magnetic-nucleus single-crystalline zeolite, which displays pronounced superparamagnetism (14 emu/g) and robust acidity (~0.83 mmol/g). This innovative material has been effectively utilized in a magnetically stabilized bed (MSB) reactor for the dehydration of ethanol, delivering an exceptional conversion rate (98 %), supreme ethylene selectivity (98 %), and superior catalytic endurance (in excess of 100 hours).

3.
Chem Rev ; 121(23): 14349-14429, 2021 12 08.
Artículo en Inglés | MEDLINE | ID: mdl-34609850

RESUMEN

Functional mesoporous materials have gained tremendous attention due to their distinctive properties and potential applications. In recent decades, the self-assembly of micelles and framework precursors into mesostructures on the liquid-solid, liquid-liquid, and gas-liquid interface has been explored in the construction of functional mesoporous materials with diverse compositions, morphologies, mesostructures, and pore sizes. Compared with the one-phase solution synthetic approach, the introduction of a two-phase interface in the synthetic system changes self-assembly behaviors between micelles and framework species, leading to the possibility for the on-demand fabrication of unique mesoporous architectures. In addition, controlling the interfacial tension is critical to manipulate the self-assembly process for precise synthesis. In particular, recent breakthroughs based on the concept of the "monomicelles" assembly mechanism are very promising and interesting for the synthesis of functional mesoporous materials with the precise control. In this review, we highlight the synthetic strategies, principles, and interface engineering at the macroscale, microscale, and nanoscale for oriented interfacial assembly of functional mesoporous materials over the past 10 years. The potential applications in various fields, including adsorption, separation, sensors, catalysis, energy storage, solar cells, and biomedicine, are discussed. Finally, we also propose the remaining challenges, possible directions, and opportunities in this field for the future outlook.


Asunto(s)
Ingeniería , Micelas , Catálisis , Porosidad
4.
J Am Chem Soc ; 144(13): 6091-6099, 2022 04 06.
Artículo en Inglés | MEDLINE | ID: mdl-35316600

RESUMEN

Synthesis of hierarchically porous structures with uniform spatial gradient and structure reinforcement effect still remains a great challenge. Herein, we report the synthesis of zeolite@mesoporous silica core-shell nanospheres (ZeoA@MesoS) with a gradient porous structure through a micellar dynamic assembly strategy. In this case, we find that the size of composite micelles can be dynamically changed with the increase of swelling agents, which in situ act as the building blocks for the modular assembly of gradient mesostructures. The ZeoA@MesoS nanospheres are highly dispersed in solvents with uniform micropores in the inner core and a gradient tubular mesopore shell. As a nanoreactor, such hierarchically gradient porous structures enable the capillary-directed fast mass transfer from the solutions to inner active sites. As a result, the ZeoA@MesoS catalysts deliver a fabulous catalytic yield of ∼75% on the esterification of long-chain carboxylic palmitic acids and high stability even toward water interference, which can be well trapped by the ZeoA core, pushing forward the chemical equilibrium. Moreover, a very remarkable catalytic conversion on the C-H arylation reaction of large N-methylindole is achieved (∼98%) by a Pd-immobilized ZeoA@MesoS catalyst. The water tolerance feature gives a notable enhancement of 26% in catalytic yield compared to the Pd-dendritic mesoporous silica without the zeolite core.


Asunto(s)
Nanosferas , Catálisis , Micelas , Nanosferas/química , Porosidad , Dióxido de Silicio/química
5.
J Am Chem Soc ; 144(45): 20964-20974, 2022 Nov 16.
Artículo en Inglés | MEDLINE | ID: mdl-36283036

RESUMEN

Precise synthesis of well-ordered ultrathin nanowire arrays with tunable active surface, though attractive in optoelectronics, remains challenging to date. Herein, well-aligned sub-10 nm TiO2 nanowire arrays with controllable corrugated structure have been synthesized by a unique monomicelle-directed assembly method. The nanowires with an exceptionally small diameter of ∼8 nm abreast grow with an identical adjacent distance of ∼10 nm, forming vertically aligned arrays (∼800 nm thickness) with a large surface area of ∼102 m2 g-1. The corrugated structure consists of bowl-like concave structures (∼5 nm diameter) that are closely arranged along the axis of the ultrathin nanowires. And the diameter of the concave structures can be finely manipulated from ∼2 to 5 nm by simply varying the reaction time. The arrays exhibit excellent charge dynamic properties, leading to a high applied bias photon-to-current efficiency up to 1.4% even at a very low potential of 0.41 VRHE and a superior photocurrent of 1.96 mA cm-2 at 1.23 VRHE. Notably, an underlying mechanism of the hole extraction effect for concave walls is first clarified, demonstrating the exact role of concave walls as the hole collection centers for efficient water splitting.

6.
J Am Chem Soc ; 144(26): 11767-11777, 2022 Jul 06.
Artículo en Inglés | MEDLINE | ID: mdl-35731994

RESUMEN

Constructing hierarchical three-dimensional (3D) mesostructures with unique pore structure, controllable morphology, highly accessible surface area, and appealing functionality remains a great challenge in materials science. Here, we report a monomicelle interface confined assembly approach to fabricate an unprecedented type of 3D mesoporous N-doped carbon superstructure for the first time. In this hierarchical structure, a large hollow locates in the center (∼300 nm in diameter), and an ultrathin monolayer of spherical mesopores (∼22 nm) uniformly distributes on the hollow shells. Meanwhile, a small hole (4.0-4.5 nm) is also created on the interior surface of each small spherical mesopore, enabling the superstructure to be totally interconnected. Vitally, such interconnected porous supraparticles exhibit ultrahigh accessible surface area (685 m2 g-1) and good underwater aerophilicity due to the abundant spherical mesopores. Additionally, the number (70-150) of spherical mesopores, particle size (22 and 42 nm), and shell thickness (4.0-26 nm) of the supraparticles can all be accurately manipulated. Besides this spherical morphology, other configurations involving 3D hollow nanovesicles and 2D nanosheets were also obtained. Finally, we manifest the mesoporous carbon superstructure as an advanced electrocatalytic material with a half-wave potential of 0.82 V (vs RHE), equivalent to the value of the commercial Pt/C electrode, and notable durability for oxygen reduction reaction (ORR).

7.
J Am Chem Soc ; 144(5): 2208-2217, 2022 Feb 09.
Artículo en Inglés | MEDLINE | ID: mdl-35099956

RESUMEN

Iridium (Ir)-based electrocatalysts are widely explored as benchmarks for acidic oxygen evolution reactions (OERs). However, further enhancing their catalytic activity remains challenging due to the difficulty in identifying active species and unfavorable architectures. In this work, we synthesized ultrathin Ir-IrOx/C nanosheets with ordered interlayer space for enhanced OER by a nanoconfined self-assembly strategy, employing block copolymer formed stable end-merged lamellar micelles. The interlayer distance of the prepared Ir-IrOx/C nanosheets was well controlled at ∼20 nm and Ir-IrOx nanoparticles (∼2 nm) were uniformly distributed within the nanosheets. Importantly, the fabricated Ir-IrOx/C electrocatalysts display one of the lowest overpotential (η) of 198 mV at 10 mA cm-2geo during OER in an acid medium, benefiting from their features of mixed-valence states, rich electrophilic oxygen species (O(II-δ)-), and favorable mesostructured architectures. Both experimental and computational results reveal that the mixed valence and O(II-δ)- moieties of the 2D mesoporous Ir-IrOx/C catalysts with a shortened Ir-O(II-δ)- bond (1.91 Å) is the key active species for the enhancement of OER by balancing the adsorption free energy of oxygen-containing intermediates. This strategy thus opens an avenue for designing high performance 2D ordered mesoporous electrocatalysts through a nanoconfined self-assembly strategy for water oxidation and beyond.

8.
Mar Drugs ; 20(10)2022 Oct 02.
Artículo en Inglés | MEDLINE | ID: mdl-36286455

RESUMEN

Glycosaminoglycan from Apostichopus japonicus (AHG) and its depolymerized fragments (DAHGs) are anticoagulant fucosylated chondroitin sulfate. The aim of this study was to further evaluate the anticoagulant and antithrombic activity of AHG and DAHGs, as well as reveal the dynamic relationship between exposure and effect in vivo. The results demonstrated that AHG100 (Mw~100 kDa), DAHG50 (Mw~50 kDa), and DAHG10 (Mw~10 kDa) exhibited potent anticoagulant activity by inhibiting intrinsic factor Xase complex (FXase) as well as antithrombin-dependent factor IIa (FIIa) and factor Xa (FXa). These glycosaminoglycans markedly prevented thrombosis formation and thrombin-induced platelet aggregation in a dose- and molecular weight-dependent manner in vitro and in vivo. The further bleeding time measurement indicated that DAHG10 exhibited obviously lower hemorrhage risks than native AHG100. Following oral administration, DAHG10 could be absorbed into blood, further dose-dependently prolonging activated partial thromboplastin time (APTT) and thrombin time (TT) as well as inhibiting FXa and FIIa partially through FXase. Anticoagulant activity was positively associated with plasma concentration following oral administration of DAHG10. Our study proposed a new point of view to understand the correlation between effects and exposure of fucosylated chondroitin sulfate as an effective and safe oral antithrombotic agent.


Asunto(s)
Anticoagulantes , Stichopus , Ratas , Animales , Anticoagulantes/farmacología , Glicosaminoglicanos/farmacología , Factor Xa , Coagulación Sanguínea , Trombina , Fibrinolíticos/farmacología , Factor Intrinseco/farmacología , Antitrombinas/farmacología
9.
Nano Lett ; 21(14): 6071-6079, 2021 07 28.
Artículo en Inglés | MEDLINE | ID: mdl-34269590

RESUMEN

Streamlined architectures with a low fluid-resistance coefficient have been receiving great attention in various fields. However, it is still a great challenge to synthesize streamlined architecture with tunable surface curvature at the nanoscale. Herein, we report a facile interfacial dynamic migration strategy for the synthesis of streamlined mesoporous nanotadpoles with varied architectures. These tadpole-like nanoparticles possess a big streamlined head and a slender tail, which exhibit large inner cavities (75-170 nm), high surface areas (424-488 m2 g-1), and uniform mesopore sizes (2.4-3.2 nm). The head curvature of the streamlined mesoporous nanoparticles can be well-tuned from ∼2.96 × 10-2 to ∼5.56 × 10-2 nm-1, and the tail length can also be regulated from ∼30 to ∼650 nm. By selectively loading the Fe3O4 catalyst in the cavity of the streamlined silica nanotadpoles, the H2O2-driven mesoporous nanomotors were designed. The mesoporous nanomotors with optimized structural parameters exhibit outstanding directionality and a diffusion coefficient of 8.15 µm2 s-1.


Asunto(s)
Nanopartículas , Dióxido de Silicio , Catálisis , Peróxido de Hidrógeno , Porosidad
10.
Angew Chem Int Ed Engl ; 61(27): e202203022, 2022 Jul 04.
Artículo en Inglés | MEDLINE | ID: mdl-35411660

RESUMEN

Mimicking natural nitrogenase to create highly efficient single-atom catalysts (SACs) for ambient N2 fixation is highly desired, but still challenging. Herein, S-coordinated Fe SACs on mesoporous TiO2 have been constructed by a lattice-confined strategy. The extended X-ray absorption fine structure and X-ray photoelectron spectroscopy spectra demonstrate that Fe atoms are anchored in TiO2 lattice via the FeS2 O2 coordination configuration. Theoretical calculations reveal that FeS2 O2 sites are the active centers for electrocatalytic nitrogen reduction reaction (NRR). Moreover, the finite element analysis shows that confinement of opened and ordered mesopores can facilitate the mass transport and offer an enlarged active surface area for NRR. As a result, this catalyst delivers a favorable NH3 yield rate of 18.3 µg h-1 mgcat. -1 with a high Faradaic efficiency of 17.3 % at -0.20 V versus a reversible hydrogen electrode. Most importantly, this lattice-confined strategy is universal and can also be applied to Ni1 Sx @TiO2 , Co1 Sx @TiO2 , Mo1 Sx @TiO2 , and Cu1 Sx @TiO2 SACs. Our study provides new hints for the design and biomimetic synthesis of highly efficient NRR electrocatalysts.

11.
Angew Chem Int Ed Engl ; 61(43): e202211307, 2022 Oct 24.
Artículo en Inglés | MEDLINE | ID: mdl-36037030

RESUMEN

A sulfhydryl monomicelles interfacial assembly strategy is presented for the synthesis of fully exposed single-atom-layer Pt clusters on 2D mesoporous TiO2 (SAL-Pt@mTiO2 ) nanosheets. This synthesis features the introduction of the sulfhydryl group in monomicelles to finely realize the controllable co-assembly process of Pt precursors within ordered mesostructures. The resultant SAL-Pt@mTiO2 shows uniform SAL Pt clusters (≈1.2 nm) anchored in ultrathin 2D nanosheets (≈7 nm) with a high surface area (139 m2 g-1 ), a large pore size (≈25 nm) and a high dispersion (≈99 %). Moreover, this strategy is universal for the synthesis of other SAL metal clusters (Pd and Au) on 2D mTiO2 with high exposure and accessibility. When used as a catalyst for hydrogenation of 4-nitrostyrene, the SAL-Pt@mTiO2 shows a high catalytic activity (TOF up to 2424 h-1 ), 100 % selectivity for 4-aminostyrene, good stability, and anti-resistance to thiourea poisoning under relatively mild conditions (25 °C, 10 bar).

12.
Bull Environ Contam Toxicol ; 107(4): 577-584, 2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-32166334

RESUMEN

Plastics are ubiquitous in the environment and have become a hot topic in academic circles. Extensive studies have focused on analytical methods, source, abundance, transport, fate, degradation of plastics in the environment and threats to natural surroundings, wildlife or even human health. However, characteristics of plastic pollution, which are critical to understand this emerging problem, remain unknown up to now. Here, this paper reviews the major characteristics of plastic pollution in the environment to enhance present understanding of this issue. These characteristics, including diversity, persistence, global issues, combined pollution and threats to organisms and human health, are critically summarized in this work. Further, "plastic cycle" in the environment, namely, aquatic, atmospheric, and terrestrial system, is also discussed in this review. Finally, we highlight current challenges of plastic pollution posed to the public and also recommend the research trends in future work.


Asunto(s)
Plásticos , Contaminantes Químicos del Agua , Monitoreo del Ambiente , Contaminación Ambiental , Humanos , Contaminantes Químicos del Agua/análisis
13.
Angew Chem Int Ed Engl ; 58(44): 15863-15868, 2019 Oct 28.
Artículo en Inglés | MEDLINE | ID: mdl-31411807

RESUMEN

A molecular design strategy is used to construct ordered mesoporous Ti3+ -doped Li4 Ti5 O12 nanocrystal frameworks (OM-Ti3+ -Li4 Ti5 O12 ) by the stoichiometric cationic coordination assembly process. Ti4+ /Li+ -citrate chelate is designed as a new molecular precursor, in which the citrate can not only stoichiometrically coordinate Ti4+ with Li+ homogeneously at the atomic scale, but also interact strongly with the PEO segments in the Pluronic F127. These features make the co-assembly and crystallization process more controllable, thus benefiting for the formation of the ordered mesostructures. The resultant OM-Ti3+ -Li4 Ti5 O12 shows excellent rate (143 mAh g-1 at 30 C) and cycling performances (<0.005 % fading per cycle). This work could open a facile avenue to constructing stoichiometric ordered mesoporous oxides or minerals with highly crystalline frameworks.

14.
J Am Chem Soc ; 140(21): 6531-6535, 2018 05 30.
Artículo en Inglés | MEDLINE | ID: mdl-29690767

RESUMEN

Distinguishing structural isomers at the single-molecule level remains a challenge. We report the single-molecule recognition of two diketopyrrolopyrrole containing isomers (SDPP and SPPO) employing the mechanically controllable break junction technique. The single-molecule conductances of the two isomers are indistinguishable under normal conditions. However, reversible protonation and deprotonation of the SPPO in molecular junction result in more than 1 order of magnitude conductance change, which dramatically enhances the conductance difference between the two isomers. Theoretical study reveals that the dramatic conductance switching is due to reversible quantum interference effect. It is suggested that combination of stimuli-response and quantum interference can be an efficient strategy to enhance isomer recognition and conductance switching in single-molecule junctions.

15.
Zhonghua Yu Fang Yi Xue Za Zhi ; 49(6): 470-4, 2015 Jun.
Artículo en Zh | MEDLINE | ID: mdl-26310328

RESUMEN

OBJECTIVE: To compare the safety of haemophilus influenzae type b (Hib) vaccine vaccination on vastus lateralis muscle and deltoid muscle of infant. METHODS: A total of 408 3-4 months old infants were divided into vastus lateralis muscle group and deltoid muscle group in Beijing, 2014. They were divided into the vastus lateralis muscle group (204) and deltoid muscle group (204) by extracting random number. Each observation object was given 3 doses of Hib vaccine according to the program. Collected systemic and local reactions after vaccination and calculated the incidence of adverse reactions. RESULTS: A total of 61 infants were quitted during the study, 1 132 doses were observed. The total reactions incidence of Vastus lateralis muscle group and Deltoid muscle group were 33.0% (186/564) and 27.6% (157/568) with no statistical differences (χ² = 3.818, P = 0.059). The two groups incidence at the same day of vaccination (day 0) which the highest were 23.2% (131/564) and 20.6% (117/568), then declined with time (linear trend test vastus lateralis muscle group χ² = 36.600, P < 0.001,deltoid muscle group χ² = 29.947, P < 0.001), day 1 were 20.4% (115/564) and 17.6% (100/568), day 2 were 16.0% (90/564) and 13.4% (76/568), day 3 were 10.3% (58/564) and 10.6% (60/568), day 4-7 were 11.2% (63/564) and 11.3% (64/568). No serious adverse events (SAE) were reported during the study. The local reactions incidence of two groups were 7.1% (40/564) and 7.7% (44/568)with no statistical differences (χ² = 0.176, P = 0.675). The systemic reactions incidence of two groups were 25.9% (146/564) and 20.6% (117/568) with obvious statistical differences (χ² = 4.437, P = 0.035). The fever incidence of vastus lateralis muscle group (11.5% (65/564)) was higher than Deltoid muscle group (4.4% (25/568)) with obvious statistical differences (χ² = 4.868, P = 0.027). The 1st dose incidence of fever and abnormal crying of vastus lateralis muscle group (fever 11.3% (23/204), abnormal crying 19.1% (39/204)) was higher than deltoid muscle group (fever 4.4% (9/204), abnormal crying 11.8% (24/204)) and the 2nd dose of diarrhea of deltoid muscle group (11.6% (22/190)) was higher than vastus lateralis muscle group (5.9% (11/187)) with obvious statistical differences (fever χ² = 15.288, P < 0.001, abnormal crying χ² = 4.224, P = 0.040, diarrhea χ² = 3.829, P = 0.046). CONCLUSION: Both vastus lateralis muscle group and deltoid muscle group had lower incidence of adverse reactions after vaccination. No serious adverse events were associated with vaccination. Vastus lateralis muscle vaccination as well as deltoid muscle vaccination demonstrated safe.


Asunto(s)
Cápsulas Bacterianas , Músculo Deltoides , Vacunas contra Haemophilus , Músculo Cuádriceps , China , Fiebre , Haemophilus influenzae tipo b , Humanos , Incidencia , Lactante , Vacunación
16.
Mol Diagn Ther ; 28(4): 455-468, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38837024

RESUMEN

PURPOSE: Globally, non-small cell lung cancer (NSCLC) is the primary cause of cancer-related mortality, both early and accurate diagnosis are essential for effective treatment and improved patient outcomes. Exosomal noncoding RNAs (ncRNAs) have emerged as promising biomarkers for NSCLC diagnosis. This meta-analysis aims to assess the diagnostic accuracy of exosomal long noncoding RNAs (lncRNAs) for diagnosing NSCLC. METHODS: A comprehensive literature search was conducted to identify relevant studies that assessed the diagnostic performance of exosomal lncRNAs in NSCLC. Quality assessment and data extraction were performed independently by two reviewers. Pooled sensitivity, specificity, and other relevant diagnostic parameters were calculated using a bivariate random-effects model. Subgroup analyses and meta-regression were conducted to explore potential sources of heterogeneity. RESULTS: Sixteen studies, comprising 1843 NSCLC cases and 1298 controls, were included in this meta-analysis. The pooled sensitivity and specificity of nine exosomal lncRNAs for diagnosing NSCLC were 0.74 [95% confidence interval (CI) 0.69-0.79] and 0.78 (95% CI 0.68-0.85). The pooled area under the receiver operating characteristic curve (AUC) for fifteen lncRNAs was 0.80 (95% CI 0.768-0.831). Meta-regression could not find any source for interstudy heterogeneity. CONCLUSION: Exosomal lncRNAs, particularly AL139294.1, GAS5, LUCAT1, and SOX2-OT, have excellent diagnostic accuracy and promising diagnostic potential in NSCLC. Therefore, they can be used as diagnostic tools for early detection of NSCLC.


Asunto(s)
Biomarcadores de Tumor , Carcinoma de Pulmón de Células no Pequeñas , Exosomas , Neoplasias Pulmonares , ARN Largo no Codificante , Humanos , ARN Largo no Codificante/genética , Carcinoma de Pulmón de Células no Pequeñas/genética , Carcinoma de Pulmón de Células no Pequeñas/diagnóstico , Exosomas/genética , Exosomas/metabolismo , Biomarcadores de Tumor/genética , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/diagnóstico , Curva ROC , Sensibilidad y Especificidad
17.
Small Methods ; : e2400069, 2024 Apr 09.
Artículo en Inglés | MEDLINE | ID: mdl-38593363

RESUMEN

Silicon (Si) is regarded as a promising anode material because of its outstanding theoretical capacity, abundant existence, and mature infrastructure, but it suffers from an inherent volume expansion problem. Herein, a facile, scalable, and cost-effective route to produce Si nanosheets (Si NSs) using a low-cost silica fume as the start materials is proposed. After coated with carbon, the as-prepared Si-NSs@C material delivers ultrahigh capability (2770 mAh g-1 at 0.1 C), high initial Coulombic efficiency (87.9%), and long cycling lifespan (100 cycles at 0.5 C with a capacity decay rate of 0.3% per cycle). Beyond proof of concept, this work demonstrates a Si-NSs based pouch cell with an impressive capacity retention of 70.9% after 400 cycles, making it more promising for practical application. Revealed by the theoretical simulation, kinetics analysis, and in situ thickness/pressure detection, it is found that the superior performance of Si-NSs is attributed to the improved diffusivity and reversibility of Li+ ions and low expansion.

18.
Natl Sci Rev ; 11(4): nwae054, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38545447

RESUMEN

Due to their uncontrollable assembly and crystallization process, the synthesis of mesoporous metal oxide single crystals remains a formidable challenge. Herein, we report the synthesis of single-crystal-like mesoporous Li2TiSiO5 by using soft micelles as templates. The key lies in the atomic-scale self-assembly and step-crystallization processes, which ensure the formation of single-crystal-like mesoporous Li2TiSiO5 microparticles via an oriented attachment growth mechanism under the confinement of an in-situ formed carbon matrix. The mesoporous Li2TiSiO5 anode achieves a superior rate capability (148 mAh g-1 at 5.0 A g-1) and outstanding long-term cycling stability (138 mAh g-1 after 3000 cycles at 2.0 A g-1) for lithium storage as a result of the ultrafast Li+ diffusion caused by penetrating mesochannels and nanosized crystal frameworks (5-10 nm). In comparison, bulk Li2TiSiO5 exhibits poor rate capability and cycle performance due to micron-scale diffusion lengths. This method is very simple and reproducible, heralding a new way of designing and synthesizing mesoporous single crystals with controllable frameworks and chemical functionalities.

19.
Environ Sci Pollut Res Int ; 30(59): 123335-123350, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37981607

RESUMEN

In recent years, green bonds have become an important part of the green financial system. In this paper, we investigate theoretically and empirically how green bond financing impacts corporate long-term value orientation. To study this relationship, we manually collect green bond financing data and use Python to construct a measure reflecting corporate long-term value. Using a sample of Chinese A-share bond issuing companies from 2016 to 2021, we find that (1) green bond financing can significantly promote companies to pursue long-term value, in which financing costs, management's strategic risk-taking, and external supervision are the underlying mechanisms. (2) There is a synergistic effect between green bond financing and environmental regulation, which can jointly improve the intensity of corporate long-term value orientation. (3) The relationship between green bond financing and corporate long-term value is more significant in enterprises with heavily polluting, lower risk-taking levels, less strategic change, and lower financial mismatch risk. Our findings reveal the "corrective" effect of green bond financing on management's strategic decision-making, which provides new empirical evidence for comprehensively and accurately evaluating the role of green bonds and promoting the development of the green bond market.


Asunto(s)
Contaminación Ambiental , Regulación Gubernamental , China , Valores Sociales , Comercio
20.
Nat Chem ; 15(6): 832-840, 2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-37055572

RESUMEN

The ability of Janus nanoparticles to establish biological logic systems has been widely exploited, yet conventional non/uni-porous Janus nanoparticles are unable to fully mimic biological communications. Here we demonstrate an emulsion-oriented assembly approach for the fabrication of highly uniform Janus double-spherical MSN&mPDA (MSN, mesoporous silica nanoparticle; mPDA, mesoporous polydopamine) nanoparticles. The delicate Janus nanoparticle possesses a spherical MSN with a diameter of ~150 nm and an mPDA hemisphere with a diameter of ~120 nm. In addition, the mesopore size in the MSN compartment is tunable from ~3 to ~25 nm, while those in the mPDA compartments range from ~5 to ~50 nm. Due to the different chemical properties and mesopore sizes in the two compartments, we achieve selective loading of guests in different compartments, and successfully establish single-particle-level biological logic gates. The dual-mesoporous structure enables consecutive valve-opening and matter-releasing reactions within one single nanoparticle, facilitating the design of single-particle-level logic systems.


Asunto(s)
Nanopartículas , Emulsiones , Nanopartículas/química , Compuestos de Diazonio , Piridinas , Dióxido de Silicio/química , Porosidad
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