Nano-structured hybrid molybdenum carbides/nitrides generated in situ for HER applications

Kumar, Rajinder; Rai, Ritu; Gautam, Seema; Sarkar, Abir De; Tiwari, Nidhi; Jha, S. N.; Bhattacharyya, D.; Ganguli, Ashok K.; Bagchi, Vivek

doi:10.1039/c7ta01815k

Cited by 64 publications

(48 citation statements)

References 34 publications

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“…The open nanostructure favors the exposure of more active sites, facilitating mass transfer and thus leading to improved catalytic activity.F urthermore, according to the density functionalt heory calculation reported previously,u niform N-doping in the carbonm atrix benefits its catalytic properties by delivering as maller DG(H*),w hich is indicativeo fh ydrogena dsorption ability and can be used as an indicator for catalytic activity. [39][40][41]…”

Section: Resultsmentioning

confidence: 99%

Sprout‐like Growth of Mesoporous Mo₂C/NC Nanonetworks as Efficient Electrocatalysts for Hydrogen Evolution

Fan

Zheng

et al. 2018

ChemCatChem

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Owing to their high surface areas, porous networks, nanosized walls, and unique electronic structure, mesoporous metal carbides with tailored nanoarchitectures are of particular interest for their prominent potential applications in various fields, including energy storage, fuel cells, and catalysis. Herein, we report a sprout‐like growth strategy for the preparation of a mesoporous β‐Mo2C nanonetwork embedded in a nitrogen‐rich carbon matrix. The nanoarchitecture can be tailored from a mesoporous Mo2C nanonetwork film into Mo2C nanoparticles embedded into the carbon layer. The as‐prepared β‐Mo2C material was demonstrated to drive a current density of 10 mA cm−2 at a low overpotential of 140 mV for the hydrogen evolution reaction (HER) in acidic conditions and to remain stable for at least 120 h. The excellent electrocatalytic performance may be from (1) mesoporous Mo2C frameworks offering numerous accessible active sites; (2) a carbon layer that protects the Mo2C from accumulation and favors electron transportation; and (3) shortened diffusion paths and ultrafine crystallinity that benefit its catalytic performance.

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Section: Resultsmentioning

confidence: 99%

Sprout‐like Growth of Mesoporous Mo₂C/NC Nanonetworks as Efficient Electrocatalysts for Hydrogen Evolution

Fan

Zheng

et al. 2018

ChemCatChem

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“…To tackle the drawback, various conductive carbon materials, such as graphene, carbon nanotube, porous carbon, etc., were introduced as framework for supporting Mo 2 C to reduce its aggregation and improve conductivity . Recently, the electrochemically active N‐doped nanocarbon matrix for Mo 2 C has been proved to be effective for improving its electrocatalytic activity, mainly due to that the N‐dopant could interact with H + better than C atoms for enhanced H + adsorption and favorably modify the electronic structures of adjacent Mo and C atoms for improved H desorption from MoH . Despite these progresses, exploring the suitable precursors to uniformly hybridize Mo and carbon source to perform the controllable preparation of well‐defined Mo 2 C nanostructure with an N‐doped nanocarbon framework is still great demand.…”

Section: Methodsmentioning

confidence: 99%

Molybdenum Carbide Nanoparticles Coated into the Graphene Wrapping N‐Doped Porous Carbon Microspheres for Highly Efficient Electrocatalytic Hydrogen Evolution Both in Acidic and Alkaline Media

et al. 2018

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Molybdenum carbide (Mo2C) is recognized as an alternative electrocatalyst to noble metal for the hydrogen evolution reaction (HER). Herein, a facile, low cost, and scalable method is provided for the fabrication of Mo2C‐based eletrocatalyst (Mo2C/G‐NCS) by a spray‐drying, and followed by annealing. As‐prepared Mo2C/G‐NCS electrocatalyst displays that ultrafine Mo2C nanopartilces are uniformly embedded into graphene wrapping N‐doped porous carbon microspheres derived from chitosan. Such designed structure offer several favorable features for hydrogen evolution application: 1) the ultrasmall size of Mo2C affords a large exposed active sites; 2) graphene‐wrapping ensures great electrical conductivity; 3) porous structure increases the electrolyte–electrode contact points and lowers the charge transfer resistance; 4) N‐dopant interacts with H+ better than C atoms and favorably modifies the electronic structures of adjacent Mo and C atoms. As a result, the Mo2C/G‐NCS demonstrates superior HER activity with a very low overpotential of 70 or 66 mV to achieve current density of 10 mA cm−2, small Tafel slope of 39 or 37 mV dec−1, respectively, in acidic and alkaline media, and high stability, indicating that it is a great potential candidate as HER electrocatalyst.

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“…i) The calculated free‐energy diagram of the HER at the equilibrium potential on the surface of various catalysts as indicated. h,i) Reproduced with permission . Copyright 2017, the Royal Society of Chemistry.…”

Section: Heterostructured Catalysts For Hermentioning

confidence: 99%

Heterostructures for Electrochemical Hydrogen Evolution Reaction: A Review

Zhao

Rui

Dou

et al. 2018

Adv Funct Materials

971

687

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Developing sustainable and renewable energy sources along with efficient energy storage and conversion technologies is vital to address environmental and energy challenges. Electrochemical water splitting coupling with gridscale renewable energy harvesting technologies is becoming one of the most promising approaches. Besides, hydrogen with the highest mass-energy density of any fuel is regarded as the ultimate clean energy carrier. The realization of practical water splitting depends heavily on the development of low-cost, highly active, and durable catalysts for hydrogen evolution reactions (HERs) and oxygen evolution reactions (OERs). Recently, heterostructured catalysts, which are generally composed of electrochemical active materials and various functional additives, have demonstrated extraordinary electrocatalytic performance toward HER and OER, and particularly a number of precious-metalfree heterostructures delivered comparable activity with precious-metal-based catalysts. Herein, an overview is presented of recent research progress on heterostructured HER catalysts. It starts with summarizing the fundamentals of HER and approaches for evaluating HER activity. Then, the design and synthesis of heterostructures, electrochemical performance, and the related mechanisms for performance enhancement are discussed. Finally, the future opportunities and challenges are highlighted for the development of heterostructured HER catalysts from the points of view of both fundamental understandings and practical applications.

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Nano-structured hybrid molybdenum carbides/nitrides generated in situ for HER applications

Abstract: A highly efficient, low-cost (precious-metal-free), highly stable nanohybrid electrocatalyst containing carbon-supported molybdenum carbide and nitride nanoparticles of size ranging from 8 to 12 nm exhibit excellent HER catalytic activity.

Cited by 64 publications

References 34 publications

Sprout‐like Growth of Mesoporous Mo₂C/NC Nanonetworks as Efficient Electrocatalysts for Hydrogen Evolution

Sprout‐like Growth of Mesoporous Mo₂C/NC Nanonetworks as Efficient Electrocatalysts for Hydrogen Evolution

Molybdenum Carbide Nanoparticles Coated into the Graphene Wrapping N‐Doped Porous Carbon Microspheres for Highly Efficient Electrocatalytic Hydrogen Evolution Both in Acidic and Alkaline Media

Heterostructures for Electrochemical Hydrogen Evolution Reaction: A Review

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Nano-structured hybrid molybdenum carbides/nitrides generated in situ for HER applications

Abstract: A highly efficient, low-cost (precious-metal-free), highly stable nanohybrid electrocatalyst containing carbon-supported molybdenum carbide and nitride nanoparticles of size ranging from 8 to 12 nm exhibit excellent HER catalytic activity.

Cited by 64 publications

References 34 publications

Sprout‐like Growth of Mesoporous Mo2C/NC Nanonetworks as Efficient Electrocatalysts for Hydrogen Evolution

Sprout‐like Growth of Mesoporous Mo2C/NC Nanonetworks as Efficient Electrocatalysts for Hydrogen Evolution

Molybdenum Carbide Nanoparticles Coated into the Graphene Wrapping N‐Doped Porous Carbon Microspheres for Highly Efficient Electrocatalytic Hydrogen Evolution Both in Acidic and Alkaline Media

Heterostructures for Electrochemical Hydrogen Evolution Reaction: A Review

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Sprout‐like Growth of Mesoporous Mo₂C/NC Nanonetworks as Efficient Electrocatalysts for Hydrogen Evolution

Sprout‐like Growth of Mesoporous Mo₂C/NC Nanonetworks as Efficient Electrocatalysts for Hydrogen Evolution