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1.
J Colloid Interface Sci ; 662: 1075-1085, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38368231

RESUMO

Sodium-ion batteries offer significant advantages in terms of low-temperature performance and safety. In this study, we present a straightforward synthetic approach to produce bimetallic selenide NiCoSe2 nanoparticles grown on a three-dimensional porous carbon framework for application as anode materials in sodium-ion batteries. This unique architecture enhances reaction kinetics and structural stability. The three-dimensional interconnected porous carbon network establishes a continuous pathway of electronic conductive, while increasing specific surface area and mitigating volume expansion. Consequently, these features expedite ion transfer and enhance electrolyte interaction. Notably, compared to CoSe, NiCoSe2 exhibits reduced ion transport distances and lower sodium diffusion barriers. Leveraging these attributes, NiCoSe2/N, Se co-doped carbon composite materials (NiCoSe2/NSC) demonstrate a high specific capacity of 320.8 mAh/g, even after 1000 cycles at 5.0 A/g, with a capacity retention rate of 85.1%. The study further delves into the revelation of the reaction mechanism and ion transport pathway through in-situ X-ray diffraction (XRD) analysis and theoretical calculations. The development of these anode materials is poised to pave the way for advancements in sodium-ion battery technology.

2.
Nat Commun ; 15(1): 1313, 2024 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-38350993

RESUMO

Donor-acceptor semiconducting polymers present countless opportunities for application in photocatalysis. Previous studies have showcased their advantages through direct bottom-up methods. Unfortunately, these approaches often involve harsh reaction conditions, overlooking the impact of uncontrolled polymerization degrees on photocatalysis. Besides, the mechanism behind the separation of electron-hole pairs (excitons) in donor-acceptor polymers remains elusive. This study presents a post-synthetic method involving the light-induced transformation of the building blocks of hyper-cross-linked polymers from donor-carbon-donor to donor-carbon-acceptor states, resulting in a polymer with a substantial intramolecular dipole moment. Thus, excitons are efficiently separated in the transformed polymer. The utility of this strategy is exemplified by the enhanced photocatalytic hydrogen peroxide synthesis. Encouragingly, our observations reveal the formation of intramolecular charge transfer states using time-resolved techniques, confirming transient exciton behavior involving separation and relaxation. This light-induced method not only guides the development of highly efficient donor-acceptor polymer photocatalysts but also applies to various fields, including organic solar cells, light-emitting diodes, and sensors.

3.
Adv Healthc Mater ; 13(2): e2301953, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37788390

RESUMO

Chronic inflammation in osteoarthritis (OA) can destroy the cartilage extracellular matrix (ECM), causing cartilage damage and further exacerbating the inflammation. Effective regulation of the inflammatory microenvironment has important clinical significance for OA alleviation and cartilage protection. Polycitrate-based polymers have good antioxidant and anti-inflammatory abilities but cannot self-polymerize to form hydrogels. Herein, a one-component multifunctional polycitrate-based (PCCGA) hydrogel for OA alleviation and cartilage protection is reported. The PCCGA hydrogel is prepared using only the PCCGA polymer by self-polymerization and exhibits multifunctional properties such as injectability, adhesion, controllable pore size and elasticity, self-healing ability, and photoluminescence. Moreover, the PCCGA hydrogel exhibits good biocompatibility, biodegradability, antioxidation by scavenging intracellular reactive oxygen species, and anti-inflammatory ability by downregulating the expression of proinflammatory cytokines and promoting the proliferation and migration of stem cells. In vivo results from an OA rat model show that the PCCGA hydrogel can effectively alleviate OA and protect the cartilage by restoring uniform articular surface and cartilage ECM levels, as well as inhibiting cartilage resorption and matrix metalloproteinase-13 levels. These results indicate that the PCCGA hydrogel, as a novel bioactive material, is an effective strategy for OA treatment and has broad application prospects in inflammation-related biomedicine.


Assuntos
Cartilagem Articular , Osteoartrite , Ratos , Animais , Antioxidantes/farmacologia , Antioxidantes/uso terapêutico , Hidrogéis/farmacologia , Hidrogéis/uso terapêutico , Cartilagem , Osteoartrite/tratamento farmacológico , Inflamação/tratamento farmacológico
4.
Adv Mater ; 36(8): e2310600, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37988721

RESUMO

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

5.
ACS Nano ; 18(1): 395-409, 2024 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-38150353

RESUMO

Hydrogel wound dressings play a crucial role in promoting the healing of drug-resistant bacterially infected wounds. However, their clinical application often faces challenges such as the use of numerous components, a complicated preparation process, and insufficient biological activity. Itaconic acid, known for its excellent biological and reaction activities, has not been extensively studied for the preparation of itaconic acid-based hydrogels and their application in infected wound healing. Therefore, there is a need to develop a multifunctional single-component itaconic acid-based hydrogel that is easy to synthesize and holds promising prospects for clinical use in promoting the healing of infected wounds. In this study, we present a single-component polyitaconate-based hydrogel (PICGI) with antibacterial, anti-inflammatory, and biological activity. The PICGI hydrogel demonstrates great potential in promoting healing of infected wounds and skin regeneration. It exhibits desirable thermosensitive, injectable, and adhesive properties, as well as broad-spectrum antibacterial activity and anti-inflammatory effects. Furthermore, the PICGI hydrogel is biocompatible and significantly enhances the migration and tube formation of endothelial cells. In the case of drug-resistant bacterially infected wounds, the PICGI hydrogel effectively inhibits bacterial infection and inflammation, promotes angiogenesis, and facilitates collagen deposition, thereby accelerating the healing and regeneration of the skin. This study highlights the promising application of the PICGI hydrogel as a single-component hydrogel in tissue repair associated with bacterial infection and inflammation. Moreover, the simplicity of its components, convenient preparation process, and sufficient biological activity make the PICGI hydrogel highly suitable for promotion and clinical application.


Assuntos
Infecções Bacterianas , Staphylococcus aureus Resistente à Meticilina , Infecção dos Ferimentos , Humanos , Hidrogéis/farmacologia , Células Endoteliais , Cicatrização , Anti-Inflamatórios , Inflamação , Antibacterianos/farmacologia , Infecção dos Ferimentos/tratamento farmacológico
6.
Small ; : e2308952, 2023 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-38072789

RESUMO

To address charge recombination in photocatalysis, the prevalent approach involves the use of noble metal cocatalysts. However, the precise factors influencing this performance variability based on cocatalyst selection have remained elusive. In this study, CdS hollow spheres loaded with distinct noble metal nanoparticles (Pt, Au, and Ru) are investigated by femtosecond transient absorption (fs-TA) spectroscopy. A more pronounced internal electric field leads to the creation of a larger Schottky barrier, with the order Pt-CdS > Au-CdS > Ru-CdS. Owing to these varying Schottky barrier heights, the interface electron transfer rate (Ke ) and efficiency (ηe ) of metal-CdS in acetonitrile (ACN) exhibit the following trend: Ru-CdS > Au-CdS > Pt-CdS. However, the trends of Ke and ηe for metal-CdS in water are different (Ru-CdS > Pt-CdS > Au-CdS) due to the influence of water, leading to the consumption of photogenerated electrons and affecting the metal/CdS interface state. Although Ru-CdS displays the highest Ke and ηe , its overall photocatalytic performance, particularly in H2 production, lags behind that of Pt-CdS due to the electron backflow from Ru to CdS. This work offers a fresh perspective on the origin of performance differences and provides valuable insights for cocatalyst design and construction.

7.
BMC Complement Med Ther ; 23(1): 427, 2023 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-38012607

RESUMO

BACKGROUND: Endometriosis is a common and complex syndrome characterized by the presence of endometrial-like tissue outside the uterus. Chinese medicine has been recently found to show good efficacy in treating endometriosis. Our previous results revealed that Maqian fruit essential oil (MQEO) could inhibit the proliferation and induce apoptosis of ectopic endometrial stromal cells (EESCs), but the mechanisms remain unclear. In this study, we aim to explore the molecular mechanism of MQEO's specific effects in EESCs. METHODS: We conducted a quantitative proteomics analysis by iTRAQ on EESCs treated with MQEO or DMSO. Then deep analysis was performed based on differentially expressed proteins, including Gene Ontology enrichment analysis, pathway enrichment analysis and protein interaction analysis. Candidate protein targets were subsequently verified by western blotting. RESULTS: Among 6575 identified proteins, 435 proteins exhibited altered expression levels in MQEO-treated EESCs. Of these proteins, most were distributed in signal transduction as well as immune system and the most significantly altered pathway was complement and coagulation cascades. Moreover, two differentially expressed proteins (Heme oxygenase 1 and Acyl-CoA 6-desaturase) were verified and they can be potential biomarkers for endometriosis treatment. CONCLUSIONS: Our proteomic analysis revealed distinct protein expression patterns induced by MQEO treatment in EESCs, highlighting the potential of MQEO for endometriosis treatment and biomarker discovery.


Assuntos
Endometriose , Óleos Voláteis , Feminino , Humanos , Endometriose/tratamento farmacológico , Endometriose/genética , Endometriose/metabolismo , Proteômica , Óleos Voláteis/farmacologia , Células Estromais/metabolismo , Células Epiteliais
8.
Angew Chem Int Ed Engl ; 62(50): e202313172, 2023 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-37908153

RESUMO

Cooperative coupling of H2 evolution with oxidative organic synthesis is promising in avoiding the use of sacrificial agents and producing hydrogen energy with value-added chemicals simultaneously. Nonetheless, the photocatalytic activity is obstructed by sluggish electron-hole separation and limited redox potentials. Herein, Ni-doped Zn0.2 Cd0.8 S quantum dots are chosen after screening by DFT simulation to couple with TiO2 microspheres, forming a step-scheme heterojunction. The Ni-doped configuration tunes the highly active S site for augmented H2 evolution, and the interfacial Ni-O bonds provide fast channels at the atomic level to lower the energy barrier for charge transfer. Also, DFT calculations reveal an enhanced built-in electric field in the heterojunction for superior charge migration and separation. Kinetic analysis by femtosecond transient absorption spectra demonstrates that expedited charge migration with electrons first transfer to Ni2+ and then to S sites. Therefore, the designed catalyst delivers drastically elevated H2 yield (4.55 mmol g-1 h-1 ) and N-benzylidenebenzylamine production rate (3.35 mmol g-1 h-1 ). This work provides atomic-scale insights into the coordinated modulation of active sites and built-in electric fields in step-scheme heterojunction for ameliorative photocatalytic performance.

9.
Phys Chem Chem Phys ; 25(44): 30319-30329, 2023 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-37908190

RESUMO

The present study reports on a computational model that systematically evaluates the effect of physical factors, including size, surface modification, and rigidity, on the nuclear uptake of nanoparticles (NPs). The NP-nucleus interaction is a crucial factor in biomedical applications such as drug delivery and cellular imaging. While experimental studies have provided evidence for the influence of size, shape, and surface modification on nuclear uptake, theoretical investigations on how these physical factors affect the entrance of NPs through the nuclear pore are lacking. Our results demonstrate that larger NPs require a higher amount of energy to enter the nucleus compared to smaller NPs. This highlights the importance of size as a critical factor in NP design for nuclear uptake. Additionally, surface modification of NPs can impact the nuclear uptake pathway, indicating the potential for tailored NP design for specific applications. Notably, our findings also reveal that the rigidity of NPs has a significant effect on the transport process. The interplay between physicochemical properties and nuclear pore is found to determine nuclear uptake efficiency. Taken together, our study provides new insights into the design of NPs for precise and controllable NP-nucleus interaction, with potential implications for the development of efficient and targeted drug delivery systems and imaging agents.


Assuntos
Nanopartículas , Nanopartículas/química , Sistemas de Liberação de Medicamentos , Modelos Moleculares , Transporte Biológico
10.
PLoS One ; 18(11): e0289278, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38033038

RESUMO

In the era of the digital economy, building an internationally competitive manufacturing industry with intelligent manufacturing as its main focus is the only way to promote the transformation of a country into a manufacturing power and achieve high-quality economic development. To explore whether Digital transformation can improve the core competitiveness of traditional manufacturing enterprises, and what factors affect this process, this study establishes the core competitiveness system of enterprises through the principal component analysis(PCA) method and discusses the above issues through the construction of a double difference model. The results of this research from China's traditional manufacturing industry are as follows. (i) The digital transformation of enterprises has significantly improved their core competitiveness and has a certain time lag effect. (ii) In the process of enterprise digital transformation, enterprise management capabilities, environmental uncertainty, and enterprise operational efficiency will positively enhance the results of enterprise digital transformation. (iii) The enhancement of core competitiveness caused by digital transformation is more significant for the market leaders and laggards. (iv) Compared with non-state-owned enterprises, the Digital Transformationn of state-owned enterprises has a more obvious effect on promoting their core competitiveness. (v) In comparison with enterprises with low government subsidies, the Digital Transformation of enterprises with high government subsidies plays a more significant role in promoting their core competitiveness. In addition, this study proposes policy guidance and practical guidance for digital transformation to accelerate the promotion of core competitiveness of traditional manufacturing industry.

11.
Chem Commun (Camb) ; 59(100): 14811-14814, 2023 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-37999930

RESUMO

NiMn2O4/C hollow spheres with sandwich-structured shells were fabricated by a hydrothermal method. Leveraging the mesoporous design of the carbon hollow spheres, NiMn2O4 nanosheets were evenly dispersed on both the inner and outer surfaces of the carbon shells. NiMn2O4/C demonstrated excellent rate capability and prolonged cycling durability for sodium ion storage.

12.
Sci Adv ; 9(40): eadg8435, 2023 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-37792928

RESUMO

Noninvasive inspection of layered structures has remained a long-standing challenge for time-resolved imaging techniques, where both resolution and contrast are compromised by prominent signal attenuation, interlayer reflections, and dispersion. Our method based on terahertz (THz) time-domain spectroscopy overcomes these limitations by offering fine resolution and a broadband spectrum to efficiently extract hidden structural and content information from layered structures. We exploit local symmetrical characteristics of reflected THz pulses to determine the location of each layer, and apply a statistical process in the spatiotemporal domain to enhance the image contrast. Its superior performance is evidenced by the extraction of alphabetic characters in 26-layer subwavelength papers as well as layer reconstruction and debonding inspection in the conservation of Terra-Cotta Warriors. Our method enables accurate structure reconstruction and high-contrast imaging of layered structures at ultralow signal-to-noise ratio, which holds great potential for internal inspection of cultural artifacts, electronic components, coatings, and composites with dozens of submillimeter layers.

13.
ACS Appl Mater Interfaces ; 15(37): 43691-43701, 2023 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-37694676

RESUMO

A sodium-ion battery, with a wide operating range, is much cheaper and safer than a lithium battery. Graphene is regarded as a promising carbon material in the preparation of anode materials. However, the large two-dimensional (2D) graphene sheets restrain the cross-plane diffusion of electrolyte ions, limiting the further improvement of rate performance. Herein, a nanohybrid of FeCo2Se4 and holey graphene (FeCo2Se4/HG) has been successfully prepared by the synchronism of pore creation and active material growth. Specifically, FeCo-oxide nanoparticles serve as the etching agents, generating in-plane nanoholes and subsequently converted into FeCo2Se4. The nanoholes provide a high density of cross-plane diffusion channels for sodium ions, serving as ionic diffusion shortcuts between different graphene layers to accelerate ion transport across the entire electrode. The unique architecture endows FeCo2Se4/HG with superior rate capability (411.2 mA h g-1 at 20 A g-1) and a specific capacity of 432.4 mA h g-1 at 2.0 A g-1 after 2000 cycles with a capacity retention rate of 92.4%. Therefore, pore engineering makes it possible for holey graphene-based electrodes to achieve outstanding rate performance and superb cycling durability.

14.
Opt Express ; 31(9): 14570-14582, 2023 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-37157318

RESUMO

A compact fiber-optic temperature sensor with hybrid interferometers enhanced by the harmonic Vernier effect was proposed, which realized 36.9 times sensitization of the sensing Fabry-Perot interferometer (FPI). The hybrid interferometers configuration of the sensor consists of a FPI and a Michelson interferometer. The proposed sensor is fabricated by splicing the hole-assisted suspended-core fiber (HASCF) to the multi-mode fiber fused with the single-mode fiber, and filling polydimethylsiloxane (PDMS) into the air hole of HASCF. The high thermal expansion coefficient of PDMS improves the temperature sensitivity of the FPI. The harmonic Vernier effect eliminates the limitation of the free spectral range on the magnification factor by detecting the intersection response of internal envelopes, and realizes the secondary sensitization of the traditional Vernier effect. Combing the characteristics of HASCF, PDMS, and first-order harmonic Vernier effect, the sensor exhibits a high detection sensitivity of -19.22 nm/°C. The proposed sensor provides not only a design scheme for compact fiber-optic sensors, but also a new strategy to enhance the optical Vernier effect.

15.
ACS Appl Mater Interfaces ; 15(22): 26882-26892, 2023 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-37246565

RESUMO

As electronic equipment develops rapidly, higher requirements are placed on electrochemical energy-storage devices. These requirements can be met by a lithium-sulfur (Li-S) battery since it has an impressive energy density of 2600 Wh kg-1 and a high theoretical specific capacity of 1675 mAh g-1. Pitifully, the sluggish redox reaction kinetics and the shuttle effect of polysulfide seriously limit its applications. Separator modification has been proven to be an effective strategy for improving the performance of Li-S batteries. Herein, we have designed a competent three-dimensional separator. It is obtained by embedding Co3Se4 nanoparticles on nitrogen-doped porous carbon (Co3Se4@N-C) by high-temperature selenization of ZIF-67, which are compounded with Ti3C2Tx by electrostatic dispersion self-assembly, and the compound is used to adjust the surface properties of a polypropylene (PP) separator. Due to the synergistic effect of the superior catalytic performance of Co3Se4@N-C and the enhancement of adsorption and conductivity bestowed by Ti3C2Tx, lithium-sulfur batteries perform excellently with the modified PP separator. Specifically, the battery with a Co3Se4@N-C/Ti3C2Tx-modified PP separator exhibits an outstanding rate performance of 787 mAh g-1 at 4C, and stable performance is maintained after 300 cycles at 2C. The density functional theory (DFT) calculations are also performed to confirm the synergistic effect of Co3Se4@N-C and Ti3C2Tx. This design integrates the merits of catalysis and adsorption and provides a new method for constructing high-performance lithium-sulfur batteries.

16.
Angew Chem Int Ed Engl ; 62(25): e202304559, 2023 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-37097440

RESUMO

The interaction between a co-catalyst and photocatalyst usually induces spontaneous free-electron transfer between them, but the effect and regulation of the transfer direction on the hydrogen-adsorption energy of the active sites have not received attention. Herein, to steer the free-electron transfer in a favorable direction for weakening S-Hads bonds of sulfur-rich MoS2+x , an electron-reversal strategy is proposed for the first time. The core-shell Au@MoS2+x cocatalyst was constructed on TiO2 to optimize the antibonding-orbital occupancy. Research results reveal that the embedded Au can reverse the electron transfer to MoS2+x to generate electron-rich S(2+δ)- active sites, thus increasing the antibonding-orbital occupancy of S-Hads in the Au@MoS2+x cocatalyst. Consequently, the increase in the antibonding-orbital occupancy effectively destabilizes the H 1s-p antibonding orbital and weakens the S-Hads bond, realizing the expedited desorption of Hads to rapidly generate a lot of visible H2 bubbles. This work delves deep into the latent effect of the photocatalyst carrier on cocatalytic activity.


Assuntos
Elétrons , Hidrogênio , Transporte de Elétrons , Adsorção , Enxofre
17.
J Colloid Interface Sci ; 640: 791-800, 2023 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-36898183

RESUMO

Pyrrhotite (FeS) is extensively investigated as the anode for low-cost sodium-ion batteries (SIBs) due to their natural abundance and high theoretical capacity. However, it suffers from significant volume expansion and poor conductivity. These problems can be alleviated by promoting sodium-ion transport and introducing carbonaceous materials. Here, FeS decorated on N, S co-doped carbon (FeS/NC) is constructed through a facile and scalable strategy, which is the best of both worlds. Moreover, to give full play to the role of the optimized electrode, ether-based and ester-based electrolytes are used for matching. Reassuringly, the FeS/NC composite displays a reversible specific capacity of 387 mAh g-1 after 1000 cycles at 5A g-1 in dimethyl ether electrolyte. The even distribution of FeS nanoparticles on the ordered framework of carbon guarantees a fast electron/Na-ion transport channel, and the reaction kinetics can be further accelerated in the dimethyl ether (DME) electrolyte, ensuring the excellent rate capability and cycling performance of FeS/NC electrodes for sodium-ion storage. This finding not only provides a reference for the introduction of carbon via in-situ growth protocol, but also demonstrates the necessity for electrolyte-electrode synergy in realizing efficient sodium-ion storage.

18.
Front Chem ; 11: 1122137, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36742034

RESUMO

Prenatal exposure to nicotine that are mainly produced from tobacco smoke has been reported to affect infants. Therefore, nicotine exposure is one of important health concerns for newborn screening. Detecting nicotine and its metabolites such as cotinine in meconium were widely used to evaluate the tobacco exposure of pregnancy. In this study, disposable wooden tips were applied for touch sampling of meconium from newborn infants, and then were directly mounted on mass spectrometer (MS) to perform rapid screening of nicotine and cotinine. Choice of extraction/spray solvents was optimized. The limits of detection, reproducibility, linear response for direct analysis of meconium were also investigated. It is found the limits of detection (S/N = 3) to be as low as 0.36 ng/mg and 1.18 ng/mg for nicotine and cotinine, respectively, while the limits of quantitation (S/N = 10) to be 1.19 ng/mg and 3.94 ng/mg for nicotine and cotinine, respectively. The relative standard deviations (RSD) were found to be at 8.4%-19.8% (n = 6) for nicotine and cotinine, a good linear range from 5-500 ng/mL (R 2 > 0.99). These analytical performances are well-accepted levels for ambient mass spectrometer analysis. In this study, evaluation of nicotine and cotinine in 22 puerpera volunteers were conducted by the established wooden-tip spray mass spectrometry (WTS-MS). These results showed that wooden-tip spray mass spectrometry would be useful for newborn screening of nicotine and cotinine in meconium with high reproducibility, speed, sensitivity, and specificity. Owing to the use of disposable wooden tips that involves no sample preparation and no chromatographic separation, our results show that wooden-tip spray mass spectrometry is a powerful tool for determination of nicotine in newborn meconium.

19.
Adv Mater ; 35(13): e2207752, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36773327

RESUMO

Graphene-based nanomaterials have sprung up as promising anode materials for sodium-ion batteries due to the intriguing properties of graphene itself and the synergic effect between graphene and active materials. However, the 2D graphene sheet only allows the rapid diffusion of sodium ions along the parallel direction while that of the vertical direction is difficult, limiting the rate capability of graphene-based electrode materials. To tackle this problem, pore-forming engineering has been employed to perforate graphene and concurrently achieve the in situ growth of Co3 Se4 nanoparticles. The generation of in-plane nanohole breaks through the physical barriers of the graphene nanosheets, enabling the fast diffusion of electrolyte ions in the longitudinal direction. In addition, this design limits the aggregation of Co3 Se4 nanoparticles because of the high affinity of Co3 Se4 on graphene. Benefiting from the high conductivity and fast ion transport bestowed by the ingenious architecture, the Co3 Se4 /holey graphene exhibits a remarkable rate performance of 519.5 mAh g-1 at 5.0 A g-1 and desirable cycle stability. Conclusions drawn from this investigation are that the transport of sodium inside the graphene-based composites is crucial for rate performance enhancement and this method is effective in modifying graphene-based nanomaterials as potential anode materials.

20.
Opt Express ; 31(4): 5940-5950, 2023 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-36823863

RESUMO

In this paper, a dual-band terahertz absorber based on metamaterial structure is designed, fabricated, and measured. The metal periodic array is located on the upper surface of a silicon wafer with a metal ground plane, while the metamaterial structure is created utilizing a square metal ring with four T-shaped metal strips loaded inside of the ring. Two absorption peaks are realized at 0.715 and 1.013 THz with high Q-factors of 152.1 and 98.3, respectively, under normal TE and TM polarized incidence. A prototype of the proposed metamaterial absorber is fabricated by electron beam lithography (EBL) and electron beam evaporation (EBE) technology. Furthermore, a terahertz time-domain spectroscopy (TDS) measurement system is employed to test the absorber sample, with good measurement results obtained. This work provides a new option for the design of multi-band terahertz metamaterial absorbers.

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