Energy-Saving Electrolytic Hydrogen Generation: Ni2P Nanoarray as a High-Performance Non-Noble-Metal Electrocatalyst

It is highly attractive but challenging to develop earth-abundant electrocatalysts for energy-saving electrolytic hydrogen generation. Herein, we report that Ni2P nanoarrays grown in situ on nickel foam (Ni2P/NF) behave as a durable high-performance non-noble-metal electrocatalyst for hydrazine oxidation reaction (HzOR) in alkaline media. The replacement of the sluggish anodic oxygen evolution reaction with such the more thermodynamically favorable HzOR enables energy-saving electrochemical hydrogen production with the use of Ni2P/NF as a bifunctional catalyst for anodic HzOR and cathodic hydrogen evolution reaction. When operated at room temperature, this two-electrode electrolytic system drives 500 mAcm(-2) at a cell voltage as low as 1.0 V with strong long-term electrochemical durability and 100% Faradaic efficiency for hydrogen evolution in 1.0m KOH aqueous solution with 0.5m hydrazine.