Enhanced electrocatalytic hydrogen evolution in alkaline saline electrolyte by NiCo foam supported iridium nanoclusters

Abstract

Developing high-performance hydrogen evolution reaction (HER) electrocatalysts working at a high current density is essential because of the increasing demand for clean and renewable hydrogen energy. Herein, we have developed Ir nanocluster-decorated macroporous NiCo foam (Ir-nc@m-NiCo) to overcome the sluggish HER kinetics for enhanced hydrogen production. Ir-nc@m-NiCo can be fabricated by a corrosion engineering method. In the mechanism of electron transfer from Ni and Co to Ir at the interface between the NiCo foam and Ir cluster, the electrons accumulated on Ir favor optimal adsorption of H* for the HER. Therefore, Ir-nc@m-NiCo exhibits excellent HER activity, reaching current densities of 500 and 1000 mA cm⁻² at low overpotentials of 101 and 146 mV, respectively, in 1.0 M KOH electrolyte. Moreover, Ir-nc@m-NiCo possesses remarkable HER activity in simulated alkaline seawater electrolytes with 1000 mA cm⁻² at 178 mV and demonstrates long-term durability with a slight potential increase after 10 hours testing under 500 mA cm⁻².