Quasi-Amorphous Metallic Nickel Nanopowder as an Efficient and Durable Electrocatalyst for Alkaline Hydrogen Evolution.

Doudou Zhang,Mingrun Li,Can Li,Hong Wang,Xiaomei Wang,Yu Qi,Shengzhong Liu,Jingying Shi

doi:10.1002/advs.201801216

Abstract

Nickel is regarded as the best alternative metal electrocatalyst to platinum for hydrogen evolution reaction (HER). Success in developing a quasi‐amorphous metallic nickel (QAMN) nanopowder catalyst using a two‐step chemical route for efficient and durable HER in alkaline solution is reported. It is found that the QAMN electrocatalyst exhibits essentially zero overpotential at the cathodic onset while delivering 10 mA cm−2 at an overpotential of only 240 mV; both performances are far better than what was reported previously using prior metallic nickel catalysts. Taking into account increased surface area, further enhanced activity is attributed to the superior intrinsic activity. Meanwhile, the QAMN catalyst shows excellent stability in accelerated and interrupted polarization in alkaline solution for tens of hours. This study provides a new chemical means to prepare amorphous metallic materials for more efficient catalysis.

Highlights

Nickel is regarded as the best alternative metal electrocatalyst to platinum for one of the most promising approaches to store the intermittent renewable hydrogen evolution reaction (HER)
Results and Discussion the electrocatalytic HER activity of MoS2 in amorphous phase was intrinsically enhanced due to more active sites of the unsaturated sulfur atoms and higher surface area in contrast to its crystalline phase.[21,22,23,24,25,26,27]. Various methods such as electrodeposition, thermal plasma, polyol process, chemical vapour deposition, chemical reduction in the liquid phase have been developed for synthesizing metallic nickel powders or thin films, they all demonstrate crystalline characteristics despite their nanoscale sizes even in isolated single-atom state.[28,29,30,31]
The QAMN catalyst demonstrates much higher electrocatalytic HER activity than its crystallized metallic nickel (CMN) counterpart prepared by the same method, which significantly outperforms the previously reported metallic nickel catalysts.[28,29,30,31,32,33,34]

Summary

FULL PAPER

Success in developing a quasi-amorphous energy.[1,2] Extensive efforts have been metallic nickel (QAMN) nanopowder catalyst using a two-step chemical route for efficient and durable HER in alkaline solution is reported. It is found that the QAMN electrocatalyst exhibits essentially zero overpotential at the cathodic onset while delivering 10 mA cm−2 at an overpotential of only 240 mV; made on the alkaline electrolysis since this technology is able to offer high purity hydrogen with great promise for largescale production at low cost.[3] most of the electrochemical water splitting both performances are far better than what was reported previously using devices used to generate hydrogen in prior metallic nickel catalysts.

Results and Discussion

Conclusion

Conflict of Interest