Direct synthesis and chemical vapor deposition of 2D carbide and nitride MXenes

Science, Год журнала: 2023, Номер 379(6638), С. 1242 - 1247

Опубликована: Март 23, 2023

Two-dimensional transition-metal carbides and nitrides (MXenes) are a large family of materials actively studied for various applications, especially in the field energy storage. MXenes commonly synthesized by etching layered ternary compounds, called MAX phases. We demonstrate direct synthetic route scalable atom-economic synthesis MXenes, including compounds that have not been from phases, reactions metals metal halides with graphite, methane, or nitrogen. The enables chemical vapor deposition growth MXene carpets complex spherulite-like morphologies form through buckling release carpet to expose fresh surface further reaction. directly showed excellent storage capacity lithium-ion intercalation.

Язык: Английский

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Ultrahigh Stable Methanol Oxidation Enabled by a High Hydroxyl Concentration on Pt Clusters/MXene Interfaces

Journal of the American Chemical Society, Год журнала: 2022, Номер 144(34), С. 15529 - 15538

Опубликована: Авг. 9, 2022

Anchoring platinum catalysts on appropriate supports, e.g., MXenes, is a feasible pathway to achieve desirable anode for direct methanol fuel cells. The authentic performance of Pt often hindered by the occupancy and poisoning active sites, weak interaction between dissolution Pt. Herein, we construct three-dimensional (3D) crumpled Ti3C2Tx MXene balls with abundant Ti vacancies confinement via spray-drying process. as-prepared clusters/Ti3C2Tx (Ptc/Ti3C2Tx) show enhanced electrocatalytic oxidation reaction (MOR) activity, including relatively low overpotential, high tolerance CO poisoning, ultrahigh stability. Specifically, it achieves mass activity up 7.32 A mgPt-1, which highest value reported date in Pt-based electrocatalysts, 42% current density retained Ptc/Ti3C2Tx even after 3000 min operative time. In situ spectroscopy theoretical calculations reveal that an electric field-induced repulsion interface accelerates combination OH- adsorption intermediates (COads) kinetics thermodynamics. Besides, this also efficiently electrocatalyze ethanol, ethylene glycol, glycerol reactions comparable stability commercial Pt/C.

Язык: Английский

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Flexible and highly‐sensitive pressure sensor based on controllably oxidized MXene

InfoMat, Год журнала: 2022, Номер 4(9)

Опубликована: Июнь 1, 2022

Abstract Conductive Ti 3 C 2 T x MXenes have been widely investigated for the construction of flexible and highly‐sensitive pressure sensors. Although inevitable oxidation solution‐processed MXene has recognized, effect irreversible on its electrical conductivity sensing properties is yet to be understood. Herein, we construct a degradable piezoresistive sensor by coating flakes with different degrees in situ onto paper substrates using dipping‐drying method. In can tune intrinsic resistance expand interlayer distance nanosheets. The partially oxidized MXene‐based exhibits high sensitivity 28.43 kPa −1 , which greater than those pristine MXene, over‐oxidized state‐of‐the‐art paper‐based Additionally, these sensors exhibit short response time 98.3 ms, good durability over 5000 measurement cycles, low force detection limit 0.8 Pa. Moreover, elements are easily degraded environmentally friendly. shows promise practical applications tracking body movements, sports coaching, remote health monitoring, human–computer interactions. image

Язык: Английский

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Water-dispersible Ti3C2Tz MXene nanosheets by molten salt etching

iScience, Год журнала: 2021, Номер 24(12), С. 103403 - 103403

Опубликована: Ноя. 7, 2021

Molten-salt etching of Ti3AlC2 MAX phase offers a promising route to produce 2D Ti3C2Tz (MXene) nanosheets without hazardous HF. However, molten-salt results in MXene clays that are not water dispersible, thus preventing further processing. This occurs because lack -OH terminal groups rendering the clay hydrophobic. Here, we demonstrate method produces water-dispersible using molten salt (SnF2) etch. In etching, SnF2 diffuses between layers form AlF3 and Sn as byproducts, separating layers. The stable, aqueous dispersion yields ζ potential -31.7 mV, introduced by KOH washing. X-ray diffraction electron microscopy confirm formation etched with substantial d-spacing compared work is first use successfully prepare colloidally stable dispersions nanosheets.

Язык: Английский

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Water-induced strong isotropic MXene-bridged graphene sheets for electrochemical energy storage

Science, Год журнала: 2024, Номер 383(6684), С. 771 - 777

Опубликована: Фев. 15, 2024

Graphene and two-dimensional transition metal carbides and/or nitrides (MXenes) are important materials for making flexible energy storage devices because of their electrical mechanical properties. It remains a challenge to assemble nanoplatelets these at room temperature into in-plane isotropic, free-standing sheets. Using nanoconfined water-induced basal-plane alignment covalent π-π interplatelet bridging, we fabricated Ti

Язык: Английский

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XPS spectra curve fittings of Ti3C2Tx based on first principles thinking

Applied Surface Science, Год журнала: 2022, Номер 593, С. 153442 - 153442

Опубликована: Апрель 19, 2022

MXenes are an interesting family of 2D materials that have the potential to meet challenges in many applications. A useful tool work understanding nature MXenes, as well exploring their capabilities, is X-ray photoelectron spectroscopy (XPS). In analyzing XPS spectra it might be necessary use curve fitting extract valuable information. However, approaches toward procedure been different studies and introductions questionable assumptions, unverified feature assignments, inconsistent led contrasting conclusions from analysis. It therefore motivated show fittings F 1s, O Ti 2p, C 1s obtained high quality Ti3C2Tx based on fundamental knowledge applied step by through strategy first principles thinking. With thinking subsequent analysis became more realistic compared what presented recent studies. The results this founded can used a model for future MXenes. advantageous general.

Язык: Английский

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Extremely high-efficiency solar steam generation, robust and scalable photothermal evaporator based on ZIF-67@MXene/rGO decorated rock wool

Journal of Materials Chemistry A, Год журнала: 2023, Номер 11(10), С. 5296 - 5308

Опубликована: Янв. 1, 2023

For the first-time, recycled RW waste is decorated with a ZIF-67, MXene and reduced graphene oxide as photothermal evaporator. Solar-thermal conversion efficiency of 153.7% was achieved under 1 sun illumination.

Язык: Английский

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Electric-field harmony in V2C/V2O5 heterointerfaces toward high-performance aqueous Zn-ion batteries

Energy storage materials, Год журнала: 2023, Номер 60, С. 102835 - 102835

Опубликована: Июнь 1, 2023

Язык: Английский

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Nanoconfinement enabled non-covalently decorated MXene membranes for ion-sieving

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

Опубликована: Июль 10, 2023

Covalent modification is commonly used to tune the channel size and functionality of 2D membranes. However, common synthesis strategies produce such modifications are known disrupt structure Herein, we report less intrusive yet equally effective non-covalent on Ti3C2Tx MXene membranes by a solvent treatment, where channels robustly decorated protic solvents via hydrogen bond network. The densely functionalized (-O, -F, -OH) allows multiple establishment its sub-1-nm induces nanoconfinement effect greatly strengthen these interactions maintaining solvent-MXene distance orientation. In ion sieving separation, as-decorated exhibit stable rejection, proton-cation (H+/Mn+) selectivity that up 50 times 30 times, respectively, higher than pristine It demonstrates feasibility methods as broad alternative for nanochannels integrated in energy-, resource- environment-related applications.

Язык: Английский

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Polycaprolactone–MXene Nanofibrous Scaffolds for Tissue Engineering

ACS Applied Materials & Interfaces, Год журнала: 2023, Номер unknown

Опубликована: Март 9, 2023

New conductive materials for tissue engineering are needed the development of regenerative strategies nervous, muscular, and heart tissues. Polycaprolactone (PCL) is used to obtain biocompatible biodegradable nanofiber scaffolds by electrospinning. MXenes, a large class 2D nanomaterials, can make polymer hydrophilic. However, an understanding how their physical properties affect potential biomedical applications still lacking. We immobilized Ti3C2Tx MXene in several layers on electrospun PCL membranes positron annihilation analysis combined with other techniques elucidate defect structure porosity scaffolds. The base was characterized presence nanopores. surface had abundant vacancies at temperatures 305-355 K, voltage resonance 8 × 104 Hz relaxation time 6.5 106 s found 20-355 K temperature interval. appearance long-lived component lifetime observed, which dependent annealing temperature. study conductivity composite wide range, including its inductive capacity components, showed possibility use MXene-coated as biomaterials. electronic defects formed were correlated biological vitro bacterial adhesion tests. Double triple coatings appropriate environment cell attachment proliferation mild antibacterial effects. A combination structural, chemical, electrical, PCL-MXene demonstrated advantage over existing engineering.

Язык: Английский

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