Electrodeposition in one step: Synthesizing Ir–Co tetradecahedral nanoparticles with high-index (311) crystal planes for enhanced catalytic activity in alkaline hydrogen evolution reaction

Electrochemical water splitting represents a viable route for hydrogen production, but its efficiency critically depends on developing effective electrocatalysts that minimize energy loss and material costs. This study introduces iridium-cobalt (Ir–Co) nanoparticles were synthesized on copper foam (CF) substrates using a one-step electrodeposition method. A comprehensive analysis was conducted on the morphology, chemical composition, and crystal structure of the electrocatalysts, along with a particular study on their electrocatalytic performance in the hydrogen evolution reaction (HER). The results demonstrate that high-index IrCo (311) crystal planes have been detected in the Ir–Co/CF electrocatalysts, which possess a tetradecahedral polycrystalline structure. The size of tetradecahedral nanoparticles is in the range of 180–250 nm. Ir–Co nanoparticles exhibit a balanced composition of approximately 49.8 at% Ir and 50.2 at% Co. The Ir–Co/CF electrocatalyst exhibits superior electrocatalytic activity in 1.0 M KOH solution, requiring only 46.8 mV overpotential to obtain a current density of 10 mA cm⁻², with a low Tafel slope of 32.65 mV·dec⁻¹. Additionally, the prolonged stability tests confirm the robustness of the Ir–Co/CF electrocatalyst, highlighting its potential for sustainable energy applications.