Rational Design of Two-Dimensional Transition Metal Carbide/Nitride (MXene) Hybrids and Nanocomposites for Catalytic Energy Storage and Conversion

ACS Nano, Journal Year: 2020, Volume and Issue: 14(9), P. 10834 - 10864

Published: Aug. 12, 2020

Electro-, photo-, and photoelectrocatalysis play a critical role toward the realization of sustainable energy economy. They facilitate numerous redox reactions in storage conversion systems, enabling production chemical feedstock clean fuels from abundant resources like water, carbon dioxide, nitrogen. One major obstacle for their large-scale implementation is scarcity cost-effective, durable, efficient catalysts. A family two-dimensional transition metal carbides, nitrides, carbonitrides (MXenes) has recently emerged as promising earth-abundant candidates large-area catalytic due to unique properties hydrophilicity, high metallic conductivity, ease by solution processing. To take full advantage these desirable properties, MXenes have been combined with other materials form MXene hybrids significantly enhanced performances beyond sum individual components. hybridization tunes electronic structure optimal binding active species improve intrinsic activity while increasing density accessibility sites. This review outlines recent strategies design industrially relevant electrocatalytic, photocatalytic, photoelectrocatalytic applications such water splitting, metal-air/sulfur batteries, dioxide reduction, nitrogen reduction. By clarifying roles material components hybrids, we provide synergistically couple associated highly durable applications. We conclude highlighting key gaps current understanding guide future hybrid designs

Language: Английский

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Energy-saving hydrogen production by chlorine-free hybrid seawater splitting coupling hydrazine degradation

Nature Communications, Journal Year: 2021, Volume and Issue: 12(1)

Published: July 7, 2021

Abstract Seawater electrolysis represents a potential solution to grid-scale production of carbon-neutral hydrogen energy without reliance on freshwater. However, it is challenged by high costs and detrimental chlorine chemistry in complex chemical environments. Here we demonstrate chlorine-free hybrid seawater splitting coupling hydrazine degradation. It yields at rate 9.2 mol h –1 g cat NiCo/MXene-based electrodes with low electricity expense 2.75 kWh per m 3 H 2 500 mA cm –2 48% lower equivalent input relative commercial alkaline water electrolysis. Chlorine electrochemistry avoided cell voltages anode protection regardless Cl – crossover. This electrolyzer meanwhile enables fast degradation ~3 ppb residual. Self-powered realized integrating low-voltage direct fuel cells or solar cells. These findings enable further opportunities for efficient conversion ocean resources while removing harmful pollutants.

Language: Английский

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3D MXene Architectures for Efficient Energy Storage and Conversion

Advanced Functional Materials, Journal Year: 2020, Volume and Issue: 30(47)

Published: June 2, 2020

Abstract 2D transition metal carbides and/or nitrides (MXenes), by virtue of high electrical conductivity, abundant surface functional groups and excellent dispersion in various solvents, are attracting increasing attention showing competitive performance energy storage conversion applications. However, like other materials, MXene nanosheets incline to stack together via van der Waals interactions, which lead limited number active sites, sluggish ionic kinetics, finally ordinary materials/devices. Constructing into 3D architectures has been proven be an effective strategy reduce restacking, thus providing larger specific area, higher porosity, shorter ion mass transport distance over normal 1D structures. In this review, the commonly used strategies for manufacturing (3D MXenes MXene‐based composites) summarized, such as template, assembly, printing, methods. Special is also given structure–property relationships their applications electrochemical conversion, including supercapacitors, rechargeable batteries, electrocatalysis. Finally, authors propose a brief perspective on future opportunities challenges architectures/devices.

Language: Английский

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Bimetal Schottky Heterojunction Boosting Energy‐Saving Hydrogen Production from Alkaline Water via Urea Electrocatalysis

Advanced Functional Materials, Journal Year: 2020, Volume and Issue: 30(21)

Published: Feb. 27, 2020

Abstract Hydrogen production via water electrocatalysis is limited by the sluggish anodic oxygen evolution reaction (OER) that requires a high overpotential. In response, urea‐assisted energy‐saving alkaline hydrogen‐production system has been investigated replacing OER with more oxidizable urea oxidation (UOR). A bimetal heterostructure CoMn/CoMn 2 O 4 as bifunctional catalyst constructed in an for both and hydrogen (HER). Based on Schottky heterojunction structure, induces self‐driven charge transfer at interface, which facilitates absorption of reactant molecules fracture chemical bonds, therefore triggering decomposition urea. As result, heterostructured electrode exhibits ultralow potentials −0.069 1.32 V (vs reversible electrode) to reach 10 mA cm −2 HER UOR, respectively, solution, full electrolysis driven delivers relatively low potential 1.51 performs stably than 15 h. This represents novel strategy Mott–Schottky hybrids electrocatalysts should inspire development sustainable energy conversion combining sewage treatment.

Language: Английский

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Self‐Supported Electrocatalysts for Practical Water Electrolysis

Advanced Energy Materials, Journal Year: 2021, Volume and Issue: 11(39)

Published: Sept. 1, 2021

Abstract Over the years, significant advances have been made to boost efficiency of water splitting by carefully designing economic electrocatalysts with augmented conductivity, more accessible active sites, and high intrinsic activity in laboratory test conditions. However, it remains a challenge develop earth‐abundant catalysts that can satisfy demands practical electrolysis, is, outstanding all‐pH electrolyte capacity, direct seawater ability, exceptional performance for overall splitting, superior large‐current‐density activity, robust long‐term durability. In this context, considering features increased species loading, rapid charge, mass transfer, strong affinity between catalytic components substrates, easily‐controlled wettability, as well as, enhanced bifunctional performance, self‐supported are presently projected be most suitable contenders massive scale hydrogen generation. review, comprehensive introduction design fabrication an emphasis on deposited nanostructured catalysts, selection various methods provided. Thereafter, recent development promising applications is reviewed from aforementioned aspects. Finally, brief conclusion delivered challenges perspectives relating promotion sustainable large‐scale production discussed.

Language: Английский

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

Advanced Functional Materials, Journal Year: 2020, Volume and Issue: 30(38)

Published: July 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.

Language: Английский

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Ultrathinning Nickel Sulfide with Modulated Electron Density for Efficient Water Splitting

Advanced Energy Materials, Journal Year: 2020, Volume and Issue: 10(41)

Published: Sept. 27, 2020

Abstract Developing nonprecious electrocatalysts via a cost‐effective methods to synergistically achieve high active sites exposure and optimized intrinsic activity remains grand challenge. Here low‐cost scaled‐up chemical etching method is developed for transforming nickel foam (NF) into highly electrocatalyst both the hydrogen evolution reaction (HER) oxygen (OER). The synthetic involves Na 2 S‐induced of NF in presence Fe, leading growth ultrathin Fe‐doped Ni 3 S arrays on substrate (Fe x 3‐ @ NF). combined experimental theoretical investigations reveal that incorporated Fe cations significantly modulate morphology surface electron density , thus boost electrochemically area, transfer, optimize hydrogen/water absorption free energy. 0.9 2.1 requires overpotentials only 72 mV at 10 mA cm −2 HER 252 100 OER 1.0 m KOH, respectively, enabling an alkaline electrolyzer low cell voltage 1.51 V drive overall water splitting. More broadly, this approach very versatile can be used synthesize other metal sulfides (e.g., Fe–Cu–S, Fe–Al–S, Fe–Ti–S).

Language: Английский

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Porous MXenes: Synthesis, structures, and applications

Nano Today, Journal Year: 2019, Volume and Issue: 30, P. 100803 - 100803

Published: Nov. 17, 2019

Language: Английский

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Regulating electronic states of nitride/hydroxide to accelerate kinetics for oxygen evolution at large current density

Nature Communications, Journal Year: 2023, Volume and Issue: 14(1)

Published: April 4, 2023

Rational design efficient transition metal-based electrocatalysts for oxygen evolution reaction (OER) is critical water splitting. However, industrial water-alkali electrolysis requires large current densities at low overpotentials, always limited by intrinsic activity. Herein, we report hierarchical bimetal nitride/hydroxide (NiMoN/NiFe LDH) array as model catalyst, regulating the electronic states and tracking relationship of structure-activity. As-activated NiMoN/NiFe LDH exhibits industrially required density 1000 mA cm-2 overpotential 266 mV with 250 h stability OER. Especially, in-situ electrochemical spectroscopic reveals that heterointerface facilitates dynamic structure to optimize structure. Operando impedance spectroscopy implies accelerated OER kinetics intermediate due fast charge transport. The mechanism revealed combination theoretical experimental studies, indicating as-activated follows lattice oxidation kinetics. This work paves an avenue develop catalysts via tuning states.

Language: Английский

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Graphene/MoS2/FeCoNi(OH)x and Graphene/MoS2/FeCoNiPx multilayer-stacked vertical nanosheets on carbon fibers for highly efficient overall water splitting

Nature Communications, Journal Year: 2021, Volume and Issue: 12(1)

Published: March 2, 2021

Abstract Development of excellent and cheap electrocatalysts for water electrolysis is great significance application hydrogen energy. Here, we show a highly efficient stable oxygen evolution reaction (OER) catalyst with multilayer-stacked hybrid structure, in which vertical graphene nanosheets (VGSs), MoS 2 nanosheets, layered FeCoNi hydroxides (FeCoNi(OH) x ) are successively grown on carbon fibers (CF/VGSs/MoS /FeCoNi(OH) ). The exhibits OER performance low overpotential 225 241 mV to attain 500 1000 mA cm −2 small Tafel slope 29.2 dec −1 . Theoretical calculation indicates that compositing FeCoNi(OH) could generate favorable electronic structure decrease the overpotential, promoting electrocatalytic activity. An alkaline electrolyzer established using CF/VGSs/MoS anode overall splitting, generates current density 100 at 1.59 V stability over h. Our catalysts have prospect electrolysis.

Language: Английский

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