Recent Advances in Oxidation Stable Chemistry of 2D MXenes

Advanced Materials, Год журнала: 2021, Номер 34(13)

Опубликована: Ноя. 24, 2021

Abstract As an emerging star of 2D nanomaterials, transition metal carbides and nitrides, named MXenes, present a large potential in various research areas owing to their intrinsic multilayer structure intriguing physico‐chemical properties. However, the fabrication application functional MXene‐based devices still remain challenging as they are prone oxidative degradation under ambient environment. Within this review, preparation methods MXenes focusing on recent investigations thermal structure–stability relationships inert, oxidizing, aqueous environments systematically introduced. Moreover, key factors that affect oxidation such as, atmosphere, temperature, composition, microstructure, environment, reviewed. Based different scenarios, strategies for avoiding or delaying proposed encourage utilization complicated environments, especially at high temperature. Furthermore, chemistry MXene‐derived oxides is analyzed, which can offer perspectives further design novel composites with unique structures being preserved.

Язык: Английский

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MXenes: New Horizons in Catalysis

ACS Catalysis, Год журнала: 2020, Номер 10(22), С. 13487 - 13503

Опубликована: Ноя. 4, 2020

Two-dimensional transition-metal carbides and nitrides, known as MXenes, have garnered increasing attention for nearly a decade by virtue of their versatile composition structure, stability under certain conditions interest in (electro)catalysis, numerous appealing properties. Given the abundance components, large surface area high laboratory-scale activities, MXenes are promising catalysts supports several heterogeneous catalytic electrocatalytic reactions. This Perspective briefly summarizes most relevant (electro)catalytic processes where hold promise competitive alternatives to traditional Pt-group catalysts. We discuss how interplay metal elements with carbon, nitrogen, various terminations modulates activity MXenes. In particular, we analyze connection between experimental simulated MXene structures differences bulk carbide extended surfaces. The great advances synthesis routes upscaling, combination realistic computational models, may give leading role current quest efficient processes.

Язык: Английский

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Single Site Cobalt Substitution in 2D Molybdenum Carbide (MXene) Enhances Catalytic Activity in the Hydrogen Evolution Reaction

Journal of the American Chemical Society, Год журнала: 2019, Номер 141(44), С. 17809 - 17816

Опубликована: Сен. 20, 2019

Two-dimensional (2D) carbides, nitrides, and carbonitrides known as MXenes are emerging materials with a wealth of useful applications. However, the range metals capable forming stable is limited mostly to early transition groups 3-6, making exploration properties inherent mid or late metal very challenging. To circumvent inaccessibility MXene phases derived from mid-to-late metals, we have developed synthetic strategy that allows incorporation such sites into host matrix. Here, report structural characterization Mo2CTx:Co phase (where Tx O, OH, F surface terminations) obtained cobalt-substituted bulk molybdenum carbide (β-Mo2C:Co) through two-step synthesis: first an intercalation gallium yielding Mo2Ga2C:Co followed by removal Ga via HF treatment. Extended X-ray absorption fine structure (EXAFS) analysis confirms Co atoms occupy Mo positions in Mo2CTx lattice, providing isolated centers without any detectable formation other cobalt-containing phases. The beneficial effect cobalt substitution on redox manifested substantially improved hydrogen evolution reaction (HER) activity, compared unsubstituted catalyst. Density functional theory (DFT) calculations attribute enhanced HER kinetics favorable binding oxygen terminated strongly influenced lattice. In addition remarkable features excellent operational stability, par best performing non-noble metal-based catalysts. Overall, our work expands compositional space family introducing material site-isolated embedded matrix Mo2CTx. approach presented here illustrates tailoring for specific application can be achieved metals.

Язык: Английский

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Surface Modification of 2D Photocatalysts for Solar Energy Conversion

Advanced Materials, Год журнала: 2022, Номер 34(23)

Опубликована: Март 9, 2022

Abstract 2D materials show many particular properties, such as high surface‐to‐volume ratio, anisotropic degree, and adjustable chemical functionality. These unique properties in have sparked immense interest due to their applications photocatalytic systems, resulting significantly enhanced light capture, charge‐transfer kinetics, surface reaction. Herein, the research progress photocatalysts based on varied compositions functions, followed by specific modification strategies, is introduced. Fundamental principles focusing harvesting, charge separation, molecular adsorption/activation 2D‐material‐based system are systemically explored. The examples described here detail use of various energy‐conversion including water splitting, carbon dioxide reduction, nitrogen fixation, hydrogen peroxide production, organic synthesis. Finally, elaborating challenges possible solutions for developing these materials, review expected provide some inspiration future used efficient energy conversions.

Язык: Английский

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Recent Progress in MXene‐Based Materials: Potential High‐Performance Electrocatalysts

Advanced Functional Materials, Год журнала: 2020, Номер 30(38)

Опубликована: Июль 7, 2020

Abstract The family of transition metal carbides, nitrides, and carbonitrides (collectively called MXenes) has been a thriving field since the first invention Ti 3 C 2 T x (MXene) in 2011. MXene is new type nanometer 2D sheet material, which exhibits great application potentials various fields due to its multiple advantages such as high specific surface area, good electrical conductivity, mechanical strength. Electrocatalysis regarded core future clean energy conversion technologies, MXene‐based materials provide inspiration for design preparation electrocatalysts with activity, selectivity, long loading life time. applications electrocatalysis, including hydrogen evolution reaction, nitrogen reduction oxygen carbon dioxide methanol oxidation reaction are summarized this review. As crucial session regarding experiments, current safer more environmentally friendly methods also discussed. Focusing on enhancement methods, key challenges opportunities next‐generation platform both fundamental research practical electrocatalysis presented. This account serves promote efforts toward development MXenes related applications.

Язык: Английский

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Ambient‐Stable Two‐Dimensional Titanium Carbide (MXene) Enabled by Iodine Etching

Angewandte Chemie International Edition, Год журнала: 2021, Номер 60(16), С. 8689 - 8693

Опубликована: Янв. 23, 2021

MXene (e.g., Ti3 C2 ) represents an important class of two-dimensional (2D) materials owing to its unique metallic conductivity and tunable surface chemistry. However, the mainstream synthetic methods rely on chemical etching MAX powders AlC2 using hazardous HF or alike, leading sheets with fluorine termination poor ambient stability in colloidal dispersions. Here, we demonstrate a fluoride-free, iodine (I2 assisted route for preparing 2D (Ti3 Tx , T=O, OH) oxygen-rich terminal groups intact lattice structure. More than 71 % are thinner 5 nm average size 1.8 μm. They present excellent thin-film 1250 S cm-1 great water at least 2 weeks. abundant oxygen electrode supercapacitors, delivering high gravimetric capacitance 293 F g-1 scan rate 1 mV s-1 superior those made from fluoride-based etchants (<290 ). Our strategy provides promising pathway facile sustainable production highly stable materials.

Язык: Английский

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MXene based emerging materials for supercapacitor applications: Recent advances, challenges, and future perspectives

Coordination Chemistry Reviews, Год журнала: 2022, Номер 462, С. 214518 - 214518

Опубликована: Март 28, 2022

Язык: Английский

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Status and Prospects of MXene‐Based Lithium–Sulfur Batteries

Advanced Functional Materials, Год журнала: 2021, Номер 31(21)

Опубликована: Март 5, 2021

Abstract Lithium–sulfur (Li–S) batteries with a theoretical energy density of 2567 Wh kg −1 are very promising next‐generation storage systems, but suffer from the insulativity sulfur and Li 2 S, shuttle effect due to dissolution migration polysulfides, lithium dendrite issue. MXenes, family 2D transition metal carbides/nitrides, which have metallic conductivity, structural variety, strong chemical adsorption ability effective catalytic for fast kinetics, inducing uniform growth Li, exhibit potential high‐performance Li–S batteries. In this review, recent progress achievements MXene‐based summarized, including use MXenes in cathode, interlayer between cathode separator, anode. The architecture construction modification as well hybridization other materials demonstrated. enhancement on electrochemical performance related mechanisms composites discussed. Finally, challenges perspectives battery application also given.

Язык: Английский

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Insights into 2D/2D MXene Heterostructures for Improved Synergy in Structure toward Next‐Generation Supercapacitors: A Review

Advanced Functional Materials, Год журнала: 2022, Номер 32(18)

Опубликована: Фев. 3, 2022

Abstract 2D interfacial heterostructures have found an unassailable status in energy storage systems, particularly supercapacitors citing the intriguing structural and electrochemical characteristics. Exactly a decade ago, MXene, promising transition metal carbide/nitride/carbonitride was to possess excellent conductivity, hydrophilicity, laudable charge opportunities, enriched surface functionalities conducive for with inherent challenging shortcomings. To substantially improve, assembled 2D/2D MXene exhibit commendable performance backed by fact of swift increase research interest. In this review, state‐of‐the‐art progress material design are investigated. Discussion is initially on fundamentals including synthesis governing properties. Particularly, different preparation electrostatic assembly, situ growth, hydrothermal treatment, objective specific strategies its implications elaborated. Especially, interface science, electrode–electrolyte interaction ion/electron dynamics synergistic enhancement MXene/rGO, MXene/LDH, MXene/metal sulfides timely investigations other architectures provided compatibility from solid‐state microsupercapacitors commerciality. conclude, well‐comprehended outlook, key challenges, prospective guidelines stretching fundamental mechanism electrolyte optimizations presented encourage advanced future generation supercapacitors.

Язык: Английский

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Two-dimensional MXenes for electrochemical capacitor applications: Progress, challenges and perspectives

Energy storage materials, Год журнала: 2020, Номер 35, С. 630 - 660

Опубликована: Ноя. 29, 2020

Язык: Английский

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