Hemi-core@frame AuCu@IrNi nanocrystals as active and durable bifunctional catalysts for the water splitting reaction in acidic media

Highly efficient and economically sustainable hydrogen production via electrocatalytic water splitting can be realized by the advent of active and durable electrocatalysts toward the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). Multimetallic nanoframe structures have received great attention as promising electrocatalysts for these reactions, because their inherent high surface area and tunable surface energy states are beneficial to the electrocatalyst performance. We envisaged that the stability and activity of multimetallic nanoframe catalysts could be simultaneously augmented by introducing an additional structural feature of activity-enhancing lattice mismatch via formation of a structure-fortifying core-shell structure. Herein, we successfully demonstrate that hemi-core@frame AuCu@IrNi nanocrystals, possessing structural features of both nanoframe and core-shell, are active and durable bifunctional catalysts toward both the OER and HER under acidic conditions. The hemicore@frame AuCu@IrNi nanocrystals exhibit superior efficient electrocatalytic performance toward the overall water splitting reaction, and show 355 mV overpotential at the current density of 10 mA cm^-2 in a 0.5 M H₂SO₄ electrolyte. The robustness of the catalysts was also verified through the long-term stability test.