scholarly journals Influences of pH and EDTA Additive on the Structure of Ni Films Electrodeposited by Using Bubble Templates as Electrocatalysts for Hydrogen Evolution Reaction

Membranes ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 165
Author(s):  
Xiangtao Yu ◽  
Jun Yang ◽  
Xiangyu Ren ◽  
Zhuyin Sui

The structure of Ni films is essential to their electrocatalytic performance for hydrogen evolution reaction (HER). The pH value and EDTA (ethylene diamine tetraacetic acid) additive are important factors for the structure control of electrodeposited metal films due to their adjustment of metal electrocrystallization and hydrogen evolution side reactions. The structures of Ni films from 3D (three-dimensional) porous to compact and flat structure are electrodeposited by adjusting solution pH values or adding EDTA. It is found that when pH value increases from 7.7 to 8.1, 3D porous films change to compact films with many protrusions. Further increasing the pH value or adding 0.1 M EDTA causes compact and flat films without protrusions to appear. When pH ≤ 7.7, hydrogen bubbles with large break-off diameter are easily adsorbed on film surface acting as porous structure templates, and the electroactive ion species, Ni2+ and Ni(NH3)n2+ complexes with low coordination number (n ≤ 3), possess high reduction overpotential, which is beneficial to forming protrusions and smaller particles. So, porous Ni films are electrodeposited. In solutions with pH ≥ 8.1 or 0.1 M EDTA, Ni(NH3)n2+ complexes with high coordination number (6 ≥ n ≥ 3) and hexadentate chelate are formed. Due to the improved wettability, bubbles with a small break-off diameter rapidly detach the film surface resulting in strong stirring. The reduction overpotential is reduced, leading to the formation of larger particles. Therefore, the solution leveling ability increases, and it is difficult to form protrusions, thus it forms a compact and flat film. The 3D porous film exhibits excellent catalytic performance for HER due to the large catalytic activity area.

RSC Advances ◽  
2021 ◽  
Vol 11 (21) ◽  
pp. 12470-12475
Author(s):  
Xinmei Liu ◽  
Chen Liang ◽  
Wenlong Yang ◽  
Chunyang Yang ◽  
Jiaqi Lin ◽  
...  

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


Author(s):  
Jin Cao ◽  
Dongdong Zhang ◽  
Xinyu Zhang ◽  
Zhiyuan Zeng ◽  
Jiaqian Qin ◽  
...  

High‐safety and low‐cost aqueous zinc‐ion batteries (ZIBs) are an exceptionally compelling technology for grid‐scale energy storage, whereas the corrosion, hydrogen evolution reaction and dendrites growth of Zn anodes plague their...


RSC Advances ◽  
2017 ◽  
Vol 7 (9) ◽  
pp. 5480-5487 ◽  
Author(s):  
Jung Eun Lee ◽  
Jaemin Jung ◽  
Taeg Yeoung Ko ◽  
Sujin Kim ◽  
Seong-Il Kim ◽  
...  

GO content tuning gradually enhanced the HER catalytic performance of the MoS2/rGO hybrids, decreasing the Tafel slope from 82 to 48 mV per decade owing to an increase of catalytically active areas and an electronic transition of MoS2.


Author(s):  
Youyi Sun ◽  
Lewen Wang ◽  
Olga Guselnikova ◽  
Oleg Semyonov ◽  
James P Fraser ◽  
...  

The hydrogen evolution reaction (HER) from water is governed by electrocatalysts used. Multiple factors such as crystal structure, composition and morphology dictate the final catalytic performance. However, as multicomponent materials...


Nanoscale ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 5072-5077 ◽  
Author(s):  
Zhenming Cao ◽  
Huiqi Li ◽  
Chenyang Zhan ◽  
Jiawei Zhang ◽  
Wei Wang ◽  
...  

Monocrystalline Pt–Ni nanocages were successfully fabricated and exhibited great catalytic activity and enhanced stability for HER in alkaline solution.


2019 ◽  
Vol 7 (46) ◽  
pp. 26378-26384 ◽  
Author(s):  
Noho Lee ◽  
Il Yong Choi ◽  
Kyung-Yeon Doh ◽  
Jaewon Kim ◽  
Hyeji Sim ◽  
...  

A hierarchical electrode consisting of edge-exposed 1T phase WS2, grown on an array of surface-modified WO3 nanohelixes (NHs), and its enhanced catalytic performance in the hydrogen evolution reaction (HER) are presented.


2020 ◽  
Vol 10 (20) ◽  
pp. 6902-6909
Author(s):  
Karthika Pichaimuthu ◽  
Anirudha Jena ◽  
Ho Chang ◽  
Chaochin Su ◽  
Ru-Shi Liu

The production of hydrogen using solar energy via a photoelectrochemical system is an effective technique for meeting present clean energy needs.


Polymers ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 1309 ◽  
Author(s):  
Wenwu Guo ◽  
Quyet Le ◽  
Amirhossein Hasani ◽  
Tae Lee ◽  
Ho Jang ◽  
...  

There has been considerable research to engineer composites of transition metal dichalcogenides with other materials to improve their catalytic performance. In this work, we present a modified solution-processed method for the formation of molybdenum selenide (MoSe2) nanosheets and a facile method of structuring composites with graphene oxide (GO) or reduced graphene oxide (rGO) at different ratios to prevent aggregation of the MoSe2 nanosheets and hence improve their electrocatalytic hydrogen evolution reaction performance. The prepared GO, rGO, and MoSe2 nanosheets were characterized by X-ray powder diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, and scanning electron microscopy. The electrocatalytic performance results showed that the pure MoSe2 nanosheets exhibited a somewhat high Tafel slope of 80 mV/dec, whereas the MoSe2-GO and MoSe2-rGO composites showed lower Tafel slopes of 57 and 67 mV/dec at ratios of 6:4 and 4:6, respectively. We attribute the improved catalytic effects to the better contact and faster carrier transfer between the edge of MoSe2 and the electrode due to the addition of GO or rGO.


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