Boosted electrolytic hydrogen production at tailor-tuned nano-dendritic Ni-doped Co foam-like catalyst

Abstract

Herein, the dynamic hydrogen bubble template (DHBT) method is used to design a microporous nano-dendritic Co film with foam-like morphology. Subsequently, Co film is doped by Ni and further electropassivated in 1.0 M KOH to develop metal/oxygenated metal interfaces, leading to a prompt water dissociation step in alkaline HER. The electropassivated nano-dendritic Ni-doped Co film is characterized by SEM, HR-TEM, XRD, EDS-mapping, ICP-OES, and XPS analyses. The electrochemical measurements show that the proposed electrocatalyst exhibits a striking activity, with an overpotential of −50 mV while operating at 10 mA cm-2, outperforming its precursors and surpassing/approaching the activity of benchmark and precious-metals-fabricated catalysts. Interestingly, the electropassivated Ni-doped Co film shows a marked enhancement towards the HER compared to the electropassivated Co film, indicating that the oxygenated Ni species play a crucial role by preserving the active metal/oxygenated metal interfaces. The obtained results introduce a promising robust catalytic material for electrolytic hydrogen production in alkaline media.