Co2P-Pt Heterostructure Interfaces for Electrocatalytic Hydrogen Evolution

Abstract Pt-based electrocatalysts are effective for the hydrogen evolution reaction (HER); however, their limited ability to facilitate water dissociation and suboptimal hydrogen binding energy (HBE) in alkaline electrolytes result in slow reaction kinetics, which hinders their cost-efficiency and practical applications. This study reports the synthesis of Co2P-Pt heterostructure nanorods using a seed-mediated growth method, producing a high density of Co2P-Pt interfacial sites. Density functional theory (DFT) calculations indicate that electronic interactions at these interfaces optimize HBE on Pt, while the interfacial sites promote water dissociation. The Co2P-Pt nanorods demonstrate an overpotential of 14 mV at 10 mA cm−2 for the HER, highlighting the potential of precisely engineered metal-metal phosphide interfaces for enhancing electrocatalytic efficiency.