scholarly journals Constructing Mono-/Di-/Tri-Types of Active Sites in MoS2 Film toward Understanding Their Electrocatalytic Activity for the Hydrogen Evolution

2019 ◽  
Vol 2 (12) ◽  
pp. 8974-8984
Author(s):  
Shusheng Xu ◽  
Jiao Xu ◽  
Yu-Zhen Liu ◽  
Yong Hua ◽  
Zewen Duan ◽  
...  
2017 ◽  
Vol 5 (6) ◽  
pp. 2504-2507 ◽  
Author(s):  
Yaxiao Guo ◽  
Changshuai Shang ◽  
Erkang Wang

The CoS2/CoSe2 hybrid catalyst exhibits superior HER electrocatalytic activity as well as excellent electrochemical durability. CoSe2/DETA nanobelts not only afford an interconnected conducting network, but also demonstrate superior HER electrocatalytic activity. High dispersion and smaller CoS2 nanoparticles on the surface can provide abundant active sites for the HER.


2015 ◽  
Vol 17 (40) ◽  
pp. 26864-26874 ◽  
Author(s):  
Debabrata Chanda ◽  
Jaromír Hnát ◽  
Ana S. Dobrota ◽  
Igor A. Pašti ◽  
Martin Paidar ◽  
...  

The RGO-modified Ni electrode exhibited outstanding activity towards HER. DFT calculations indicate that H atoms, formed upon H2O discharge on Ni, spill onto the RGO, enabling continuous clearance of Ni-active sites.


2017 ◽  
Vol 5 (37) ◽  
pp. 19752-19759 ◽  
Author(s):  
Long Zhang ◽  
Tao Wang ◽  
Lan Sun ◽  
Yunjin Sun ◽  
Tingwei Hu ◽  
...  

A 3D hierarchical structure of MoSe2/NiSe2 exhibits superior HER activity because of more active sites and faster transfer of electrons.


Nanoscale ◽  
2015 ◽  
Vol 7 (12) ◽  
pp. 5157-5163 ◽  
Author(s):  
Dong Young Chung ◽  
Joung Woo Han ◽  
Dong-Hee Lim ◽  
Jun-Ho Jo ◽  
Sung Jong Yoo ◽  
...  

Structure effects of NiS and Ni3S2 nanoparticles were investigated for their electrocatalytic activity in the hydrogen evolution reaction in both acid and alkaline media.


Coatings ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 85 ◽  
Author(s):  
Edita Vernickaitė ◽  
Oksana Bersirova ◽  
Henrikas Cesiulis ◽  
Natalia Tsyntsaru

The given research was driven by prospects to design Mo-rich coatings with iron group metals electrodeposited from a highly saturated ammonium acetate bath. The obtained coatings could be employed as prominent electrodes for the hydrogen evolution reaction (HER). It was found that the Mo content in Ni–Mo alloys can be tuned from 30 to 78 at.% by decreasing the molar ratio [Ni(II)]:[Mo(VI)] in the electrolyte from 1.0 to 0.25 and increasing the cathodic current density from 30 to 100 mA/cm2. However, dense cracks and pits are formed due to hydrogen evolution at high current densities and that diminishes the catalytic activity of the coating for HER. Accordingly, smoother and crack-free Ni–54 at.% Mo, Co–52 at.% Mo and Fe–54 at.% Mo alloys have been prepared at 30 mA/cm2. Their catalytic behavior for HER has been investigated in a 30 wt.% NaOH solution at temperatures ranging from 25 to 65 °C. A significant improvement of electrocatalytic activity with increasing bath temperature was noticed. The results showed that the sequence of electrocatalytic activity in alkaline media decreases in the following order: Co–52 at.% Mo > Ni–54 at.% Mo > Fe–54 at.% Mo. These peculiarities might be linked with different catalytic behavior of formed intermetallics (and active sites) in electrodeposited alloys. The designed electrodeposited Mo-rich alloys have a higher catalytic activity than Mo and Pt cast metals.


2020 ◽  
Vol 8 (44) ◽  
pp. 23323-23329
Author(s):  
Jing Hu ◽  
Siwei Li ◽  
Yuzhi Li ◽  
Jing Wang ◽  
Yunchen Du ◽  
...  

Crystalline–amorphous Ni–Ni(OH)2 core–shell assembled nanosheets exhibit outstanding electrocatalytic activity and stability for hydrogen evolution under alkaline conditions.


2019 ◽  
Author(s):  
Yan Wang ◽  
Sagar Udyavara ◽  
Matthew Neurock ◽  
C. Daniel Frisbie

<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>


2021 ◽  
Author(s):  
Zihao Liu ◽  
Shifeng Li ◽  
Fangfang Wang ◽  
Mingxia Li ◽  
Yonghong Ni

FeNi-layered double hydroxide (LDH) is thought to be an excellent electrocatalyst for oxygen evolution reaction (OER), but it always shows extremely poor electrocatalytic activity toward hydrogen evolution reaction (HER) in...


2020 ◽  
Vol 15 (1) ◽  
Author(s):  
Pengyuan Wu ◽  
Gangyong Sun ◽  
Yuanzhi Chen ◽  
Wanjie Xu ◽  
Hongfei Zheng ◽  
...  

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