Electrodeposition of Stable Noble-Metal-Free Co-P Electrocatalysts for Hydrogen Evolution Reaction.

Hydrogen production via water splitting has been extensively explored over the past few decades, and considerable effort has been directed toward finding more reactive and cost-effective electrocatalysts by engineering their compositions, shapes, and crystal structures. In this study, we developed hierarchical cobalt phosphide (Co-P) nanosphere assemblies as non-noble metal electrocatalysts via one-step electrodeposition. The morphologies of the Co-P nanostructures and their electrocatalytic activities towards the hydrogen evolution reactions (HER) were controlled by the applied potentials during electrodeposition. The physicochemical properties of the as-prepared Co-P nanostructures in this study were characterized by field-emission scanning electron microscopy, X-ray photoemission spectroscopy and X-ray diffraction. Linear sweep voltammetry revealed that the Co-P grown at -0.9 V showed the best HER performance exhibiting the highest electrochemical active surface area and lowest interfacial charge transfer resistance. The Co-P electrocatalysts showed superior long-term stability to electrodeposited Pt, indicating their potential benefits.