Electrodeposited Ni-Co-P Triple-Layered Structure as A Robust and Durable Electrocatalyst for Hydrogen Evolution

Designing Earth-abundant, cost-effective catalysts for hydrogen evolution via water splitting is essential for hydrogen generation. Adding a third metal element to binary phosphides provides the opportunity to tune their morphology, crystalline and electronic structures and thus their electrocatalytic properties. In this study, a hierarchical crystalline/amorphous Ni-Co-P compound is prepared on nickel foam (NF) with different nickel to cobalt ratio by one-step electrodepositing technique. The Ni-Co-P/NF is composed of metallic Co and amorphous phosphides. It has hierarchical morphology, consisting of & SIM;800 nm spherical particles in the bottom layer, & SIM;1.5 & mu;m spherical particles in the middle layer, and staggered network structure on the top layer. The Ni-Co-P/NF electrode exhibits superior hydrogen evolution reaction (HER) catalytic activity in the alkaline solution, which requires only 72 mV for delivering 10 mA cm-2. More importantly, the Ni-Co-P/NF catalyst sustains the current density of 20 mAcm-2 for 53 h with negligible degradation in overpotential which shows remarkable electrochemical stability. The hierarchical crystalline/amorphous Ni-Co-P compound is prepared on nickel foam (NF) by one-step electrodepositing technique.The Ni-Co-P/NF electrode exhibits a low overpotential of 72 mV at a current density of 10 mA cm-2 and a small Tafel slope of 92 mV dec-1.The Ni-Co-P/NF shows high stability at a current density of 20 mA cm-2 for 53 h.