Construction of hierarchical and self-supported NiFe-Pt3Ir electrode for hydrogen production with industrial current density

Rational design and fabrication of electrocatalysts from the perspective of mass transfer and electronic structure is highly desirable for hydrogen evolution reaction (HER). Herein, a hierarchical and self-supported electrode comprising Cu nanowires, NiFe nanosheets, and Pt3Ir alloy nanoparticles (Cu [email protected]3Ir) was in situ constructed and established as a highly active and robust electrocatalyst for HER with industrial current densities. Benefiting from the hierarchical structure, abundant active sites, and positive electronic interaction between NiFe and Pt3Ir, the Cu [email protected]3Ir electrode shows extremely low overpotentials of 210 and 239 mV to reach industrial current densities of 500 and 1000 mA cm−2 in 1.0 M KOH solution, respectively. More importantly, Cu [email protected]3Ir electrode shows robust durability with a slight increment of 8 mV for the required potential after consecutive tests for 7 days under 500 mA cm−2. As further revealed by electrochemical and theoretical studies, the reaction kinetics of NiFe is greatly promoted by coupling with Pt3Ir, and the d-band center energy level of Pt 5d orbital is lowered by Ir atom, which not only facilitates the electron consumption at the electrode/electrolyte interface but also optimizes the energies for H adsorption and H2 desorption. This work provides valuable insights into the construction of self-supported electrodes with extraordinary activity and durability for industrial applications.