High-efficient and low-cost catalyst for hydrogen evolution reaction: Nickel phosphide nano-spheres

Abstract

Catalysts have been a bottleneck in hydrogen evolution reaction (HER) - a half reaction of water splitting. Hitherto, the most efficient HER catalyst in terms of catalytic capacity remains to be platinum group metals, especially platinum; however, rare metals' exorbitant cost and scarcity inhibit their further application in industry, which therefore call for catalysts prepared from earth-abundant elements. Herein, we introduce nickel phosphide nano-spheres (NPNs) bearing excellent HER activity. Prepared via a facile, inexpensive, and eco-friendly preparation procedure, the as-synthesized NPNs have perfect over-potential to reach −100 mA/cm2 (η100), with η100 reaching 251 mV in 0.5 M H2SO4. A series of durability tests, including cyclic voltammetry and chronoamperometry, also indicate NPNs' favorable stability in both acidic and alkaline conditions. After taking into account a string of factors, including NPNs' mass density, handy preparation process, superior catalytic activity, and favorable durability, the NPNs bear probable potentiality of taking traditional noble metals' place as the HER catalyst and are worth studying further.