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

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 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.