Interconnected urchin-like cobalt phosphide microspheres film for highly efficient electrochemical hydrogen evolution in both acidic and basic media

Abstract

There is an urgent need for active and cost-effective catalysts for electrochemical hydrogen evolution reactions to solve global energy issues. In this study, we report the development of interconnected urchin-like cobalt phosphide microspheres film on Ti foil (u-CoP/Ti) as a monolithic hydrogen-evolving catalyst electrode with high activity and strong durability under acidic and alkaline conditions. It affords 10 mA cm⁻² at overpotentials as low as 45 mV with the maintenance of its catalytic activity for at least 15 h in 0.5 M H₂SO₄, outperforming all reported CoP catalysts. When operated in 1.0 M KOH, u-CoP/Ti is also highly active and demands overpotential of 60 mV to drive 10 mA cm⁻² with strong durability.