The Influence of Temperature of Electrodeposition on the Electrochemical Properties of Ni Coatings

2015 ◽  
Vol 228 ◽  
pp. 242-245
Author(s):  
Magdalena Popczyk ◽  
Bożena Łosiewicz

Porous Ni coatings were prepared by galvanostatic electrodeposition on the steel substrate from the Watts type bath at the deposition current densityjdep= -250 mA cm2at the temperature 40, 50 and 60°C. Investigations of hydrogen evolution reaction (HER) on the obtained Ni electrodes were carried out in 5 M KOH solution at room temperature. It was found that with the increase in the electrodeposition temperature of the coatings, the activity of the Ni electrocatalysts towards the HER decreased due to diminishing surface development of the Ni coatings.

Crystals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1040 ◽  
Author(s):  
Getachew Solomon ◽  
Raffaello Mazzaro ◽  
Vittorio Morandi ◽  
Isabella Concina ◽  
Alberto Vomiero

Molybdenum sulfide (MoS2) has emerged as a promising catalyst for hydrogen evolution applications. The synthesis method mainly employed is a conventional hydrothermal method. This method requires a longer time compared to other methods such as microwave synthesis methods. There is a lack of comparison of the two synthesis methods in terms of crystal morphology and its electrochemical activities. In this work, MoS2 nanosheets are synthesized using both hydrothermal (HT-MoS2) and advanced microwave methods (MW-MoS2), their crystal morphology, and catalytical efficiency towards hydrogen evolution reaction (HER) were compared. MoS2 nanosheet is obtained using microwave-assisted synthesis in a very short time (30 min) compared to the 24 h hydrothermal synthesis method. Both methods produce thin and aggregated nanosheets. However, the nanosheets synthesized by the microwave method have a less crumpled structure and smoother edges compared to the hydrothermal method. The as-prepared nanosheets are tested and used as a catalyst for hydrogen evolution results in nearly similar electrocatalytic performance. Experimental results showed that: HT-MoS2 displays a current density of 10 mA/cm2 at overpotential (−280 mV) compared to MW-MoS2 which requires −320 mV to produce a similar current density, suggesting that the HT-MoS2 more active towards hydrogen evolutions reaction.


2021 ◽  
pp. 2151018
Author(s):  
Cihan Kuru

In this study, aged Co–Mo (3:10) alloy film has been demonstrated as an efficient and durable catalyst for hydrogen evolution reaction (HER) in acidic solution. The Co–Mo alloy films with varying Co/Mo atomic ratios have been deposited by magnetron sputtering. The catalytic activity of Mo film is outperformed by the Co–Mo alloys, among which the Co–Mo (3:10) alloy exhibits the highest HER activity with an overpotential of 310 mV at 10 mA cm[Formula: see text] current density, exchange current density of 1.74 × 10[Formula: see text] A cm[Formula: see text] and a Tafel slope of 61 mV dec[Formula: see text]. Combined with the good stability provided by the surface oxide layer, the aged Co–Mo (3:10) alloy is a promising catalyst for HER in acidic solutions.


2020 ◽  
Vol 5 (2) ◽  
pp. 565-572
Author(s):  
R. Z. Wang ◽  
Yanning Zhang

Induced high-spin Co2+ atoms on Co3S4(001) activate the electrochemical properties of adjacent S atoms for the highly-efficient HER.


2020 ◽  
Vol 65 (2) ◽  
pp. 123-130 ◽  
Author(s):  
Sen Xue ◽  
Zhibo Liu ◽  
Chaoqun Ma ◽  
Hui-Ming Cheng ◽  
Wencai Ren

2015 ◽  
Vol 228 ◽  
pp. 269-272 ◽  
Author(s):  
Magdalena Popczyk ◽  
B. Łosiewicz

The Ni-Mo alloy coatings with a high content of Mo up to 44.5 at.%, were prepared by galvanostatic electrodeposition in the range of deposition current density, jdep, from-30 to-240 mA cm-2 from the nickel plating bath containing potassium pyrophosphate, nickel chloride, sodium molybdate, and sodium bicarbonate. Investigations of hydrogen evolution reaction (HER) were carried out in 5 M KOH solution at room temperature using steady-state polarization and electrochemical impedancy spectroscopy (EIS) measurements. It was found that for the Ni-Mo alloy coatings, the increase in their catalytic properties towards the HER with the increase in the value of jdep of the coatings, was due to the intrinsic activity.


2018 ◽  
Vol 54 (71) ◽  
pp. 9901-9904 ◽  
Author(s):  
Ting Ouyang ◽  
An-Na Chen ◽  
Zhen-Zhao He ◽  
Zhao-Qing Liu ◽  
Yexiang Tong

Atomically dispersed Ni in β-Mo2C (Ni/β-Mo2C) is designed as an efficient catalyst for the HER at all pH values. The remarkable electrochemical properties of Ni/β-Mo2C are mainly attributed to the synergistic effect between atomically dispersed Ni species and β-Mo2C.


2020 ◽  
Vol MA2020-01 (46) ◽  
pp. 2604-2604
Author(s):  
Daniel Lee Parr ◽  
Kasun Dadallagei ◽  
Sidney J. DeBie ◽  
Joshua R Coduto ◽  
Christian D Haas ◽  
...  

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