Cyanogroup Functionalized Sub-2 nm Ultrafine Pt Nanonetworks Reinforce Electrocatalytic Hydrogen Evolution in A Broad pH Range

CrystEngComm ◽  
2021 ◽  
Author(s):  
Qicheng Liu ◽  
Xuan Wang ◽  
Jiaqi Liu ◽  
Xinyi Zhou ◽  
Qingwei Meng ◽  
...  
Keyword(s):  
Hydrogen Evolution ◽  
Metal Surface ◽  
Noble Metal ◽  
Surface Functionalization ◽  
Density Functional ◽  
Intermediate Species ◽  
Adsorption And Desorption ◽  
Ph Range ◽  
Desorption Capacity

Surface functionalization is an effective way to improve the activity of electrocatalysts by adjusting the adsorption and desorption capacity of intermediate species on the noble metal surface. Herein, density functional...

scholarly journals Electrocatalytic hydrogen evolution on the noble metal-free MoS2/carbon nanotube heterostructure: a theoretical study

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Farhad Keivanimehr ◽  
Sajjad Habibzadeh ◽  
Alireza Baghban ◽  
Amin Esmaeili ◽  
Ahmad Mohaddespour ◽  
...  
Keyword(s):  
Hydrogen Evolution ◽  
Noble Metal ◽  
Electrocatalytic Activity ◽  
Density Functional ◽  
Minimum Energy ◽  
Chemical Properties ◽  
Binding Energies ◽  
Functional Theory ◽  
Metal Free ◽  
Physico Chemical

AbstractMolybdenum disulfide (MoS2) is considered as a promising noble-metal-free electrocatalyst for the Hydrogen Evolution Reaction (HER). However, to effectively employ such material in the HER process, the corresponding electrocatalytic activity should be comparable or even higher than that of Pt-based materials. Thus, efforts in structural design of MoS2 electrocatalyst should be taken to enhance the respective physico-chemical properties, particularly, the electronic properties. Indeed, no report has yet appeared about the possibility of an HER electrocatalytic association between the MoS2 and carbon nanotubes (CNT). Hence, this paper investigates the synergistic electrocatalytic activity of MoS2/ CNT heterostructure for HER by Density Functional Theory simulations. The characteristics of the heterostructure, including density of states, binding energies, charge transfer, bandgap structure and minimum-energy path for the HER process were discussed. It was found that regardless of its configuration, CNT is bound to MoS2 with an atomic interlayer gap of 3.37 Å and binding energy of 0.467 eV per carbon atom, suggesting a weak interaction between CNT and MoS2. In addition, the energy barrier of HER process was calculated lower in MoS2/CNT, 0.024 eV, than in the MoS2 monolayer, 0.067 eV. Thus, the study elaborately predicts that the proposed heterostructure improves the intrinsic electrocatalytic activity of MoS2.

Surface Functionalization of g-C3N4: Molecular-Level Design of Noble-Metal-Free Hydrogen Evolution Photocatalysts

2015 ◽  
Vol 21 (29) ◽  
pp. 10290-10295 ◽  
Author(s):  
Yin Chen ◽  
Bin Lin ◽  
Weili Yu ◽  
Yong Yang ◽  
Shahid M. Bashir ◽  
...  
Keyword(s):  
Hydrogen Evolution ◽  
Noble Metal ◽  
Surface Functionalization ◽  
Molecular Level ◽  
Metal Free ◽  
Free Hydrogen ◽  
Level Design

Frontispiece: Surface Functionalization of g-C3N4: Molecular-Level Design of Noble-Metal-Free Hydrogen Evolution Photocatalysts

2015 ◽  
Vol 21 (29) ◽  
pp. n/a-n/a ◽  
Author(s):  
Yin Chen ◽  
Bin Lin ◽  
Weili Yu ◽  
Yong Yang ◽  
Shahid M. Bashir ◽  
...  
Keyword(s):  
Hydrogen Evolution ◽  
Noble Metal ◽  
Surface Functionalization ◽  
Molecular Level ◽  
Metal Free ◽  
Free Hydrogen ◽  
Level Design

Field Effect Modulation of Electrocatalytic Hydrogen Evolution at Back-Gated Two-Dimensional MoS2 Electrodes

2019 ◽  
Author(s):  
Yan Wang ◽  
Sagar Udyavara ◽  
Matthew Neurock ◽  
C. Daniel Frisbie
Keyword(s):  
Electric Field ◽  
Hydrogen Evolution ◽  
Active Sites ◽  
Density Functional ◽  
Electrode Materials ◽  
Density Functional Theory Calculations ◽  
Electronic Charge ◽  
Back Side ◽  
Gate Electrode ◽  
Conventional Manner

<div> <div> <div> <p> </p><div> <div> <div> <p>Electrocatalytic activity for hydrogen evolution at monolayer MoS2 electrodes can be enhanced by the application of an electric field normal to the electrode plane. The electric field is produced by a gate electrode lying underneath the MoS2 and separated from it by a dielectric. Application of a voltage to the back-side gate electrode while sweeping the MoS2 electrochemical potential in a conventional manner in 0.5 M H2SO4 results in up to a 140-mV reduction in overpotential for hydrogen evolution at current densities of 50 mA/cm2. Tafel analysis indicates that the exchange current density is correspondingly improved by a factor of 4 to 0.1 mA/cm2 as gate voltage is increased. Density functional theory calculations support a mechanism in which the higher hydrogen evolution activity is caused by gate-induced electronic charge on Mo metal centers adjacent the S vacancies (the active sites), leading to enhanced Mo-H bond strengths. Overall, our findings indicate that the back-gated working electrode architecture is a convenient and versatile platform for investigating the connection between tunable electronic charge at active sites and overpotential for electrocatalytic processes on ultrathin electrode materials.</p></div></div></div><br><p></p></div></div></div>

2,2’-Dipyridylamine as Organic Molecular Electrocatalyst for Hydrogen Evolution Reaction in Acidic Electrolytes

2019 ◽  
Author(s):  
Xi Yin ◽  
Ling Lin ◽  
Hoon T. Chung ◽  
Ulises Martinez ◽  
Andrew M. Baker ◽  
...  
Keyword(s):  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Density Functional ◽  
Low Cost ◽  
Membrane Electrode Assembly ◽  
Carbon Surface ◽  
Membrane Electrode ◽  
Durability Test ◽  
Onset Potential ◽  
Precious Metal Catalysts

Finding a low-cost and stable electrocatalyst for hydrogen evolution reaction (HER) as a replacement for scarce and expensive precious metal catalysts has attracted significant interest from chemical and materials research communities. Here, we demonstrate an organic catalyst based on 2,2’-dipyridylamine (dpa) molecules adsorbed on carbon surface, which shows remarkable hydrogen evolution activity and performance durability in strongly acidic polymer electrolytes without involving any metal. The HER onset potential at dpa adsorbed on carbon has been found to be less than 50 mV in sulfuric acid and in a Nafion-based membrane electrode assembly (MEA). At the same time, this catalyst has shown no performance loss in a 60-hour durability test. The HER reaction mechanisms and the low onset overpotential in this system are revealed based on electrochemical study. Density functional theory (DFT) calculations suggest that the pyridyl-N functions as the active site for H adsorption with a free energy of -0.13 eV, in agreement with the unusually low onset overpotential for an organic molecular catalyst.<br>

2,2’-Dipyridylamine as Organic Molecular Electrocatalyst for Hydrogen Evolution Reaction in Acidic Electrolytes

2019 ◽  
Author(s):  
Xi Yin ◽  
Ling Lin ◽  
Hoon T. Chung ◽  
Ulises Martinez ◽  
Andrew M. Baker ◽  
...  
Keyword(s):  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Density Functional ◽  
Low Cost ◽  
Membrane Electrode Assembly ◽  
Carbon Surface ◽  
Membrane Electrode ◽  
Durability Test ◽  
Onset Potential ◽  
Precious Metal Catalysts

Finding a low-cost and stable electrocatalyst for hydrogen evolution reaction (HER) as a replacement for scarce and expensive precious metal catalysts has attracted significant interest from chemical and materials research communities. Here, we demonstrate an organic catalyst based on 2,2’-dipyridylamine (dpa) molecules adsorbed on carbon surface, which shows remarkable hydrogen evolution activity and performance durability in strongly acidic polymer electrolytes without involving any metal. The HER onset potential at dpa adsorbed on carbon has been found to be less than 50 mV in sulfuric acid and in a Nafion-based membrane electrode assembly (MEA). At the same time, this catalyst has shown no performance loss in a 60-hour durability test. The HER reaction mechanisms and the low onset overpotential in this system are revealed based on electrochemical study. Density functional theory (DFT) calculations suggest that the pyridyl-N functions as the active site for H adsorption with a free energy of -0.13 eV, in agreement with the unusually low onset overpotential for an organic molecular catalyst.<br>

scholarly journals CoMn phosphide encapsulated in nitrogen-doped graphene for electrocatalytic hydrogen evolution over a broad pH range

2021 ◽  
Author(s):  
Jingjing Liu ◽  
Wenyao Li ◽  
Zhe Cui ◽  
Jiaojiao Li ◽  
Fang Yang ◽  
...  
Keyword(s):  
Hydrogen Evolution ◽  
Core Shell ◽  
Nitrogen Doped ◽  
Nitrogen Doped Graphene ◽  
Doped Graphene ◽  
Ph Range ◽  
Excellent Stability

A core–shell CoMn-P@NG heterostructure electrode demonstrated impressive performance of hydrogen evolution over a broad pH range and maintained excellent stability.

Adsorption of the Gas Molecules (NH3, C2H6O, C3H6O, CO, H2S) on noble metal (Ag, Au, Pt, Pd, Ru)–Doped MoSe2 Monolayer: A First-Principles Study

2021 ◽  
Author(s):  
Lanjuan Zhou ◽  
Sujing Yu ◽  
Yan Yang ◽  
Qi Li ◽  
Tingting Li ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Noble Metal ◽  
First Principles ◽  
Density Functional ◽  
Noble Metals ◽  
Gas Sensing ◽  
Functional Theory ◽  
First Principles Study ◽  
Gas Molecules ◽  
Sensing Performance

In this paper, the effects of five noble metals (Au, Pt, Pd, Ag, Ru) doped MoSe2 on improving gas sensing performance were predicted through density functional theory (DFT) based on...

scholarly journals A monodispersed CuPt alloy: synthesis and its superior catalytic performance in the hydrogen evolution reaction over a full pH range

RSC Advances ◽  
2021 ◽  
Vol 11 (21) ◽  
pp. 12470-12475
Author(s):  
Xinmei Liu ◽  
Chen Liang ◽  
Wenlong Yang ◽  
Chunyang Yang ◽  
Jiaqi Lin ◽  
...  
Keyword(s):  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
High Stability ◽  
Low Cost ◽  
Catalytic Performance ◽  
Ph Range

An effective approach to achieve the low cost and high stability of electro-catalysts for HER.

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