Superior alkaline hydrogen evolution electrocatalysis enabled by an ultrafine PtNi nanoparticle-decorated Ni nanoarray with ultralow Pt loading

The development of efficient hydrogen evolution reaction (HER) catalysts is of great importance for electrolytic hydrogen production in alkaline media. In this communication, we report the development of an ultrafine PtNi nanoparticle-decorated Ni nanosheet array with ultralow Pt loading (7.7 wt%) as a superior electrocatalyst for the alkaline HER. Such a nanoarray drives a geometrical current density of 10 mA cm(-2) at an overpotential as low as 38 mV in 0.1 M KOH, outperforming commercial 20 wt% Pt/C and all reported HER electrocatalysts. Remarkably, it also shows outstanding long-term electrochemical durability with a faradaic efficiency close to 100%. This work provides us with an attractive ultralow-Pt-content catalyst material in water-splitting devices toward high-performance and durable electrochemical production of hydrogen fuels.