Single-Atom Ir-Anchored 3D Amorphous NiFe Nanowire@Nanosheets for Boosted Oxygen Evolution Reaction

The establishment of advanced electrocatalysts with remarkable performance and cost effectiveness for the oxygen evolution reaction (OER) is an emerging need for the production of clean hydrogen fuel. In this work, three-dimensional (3D) amorphous NiFeIr_x/Ni core-shell nanowire@nanosheets (NW@NSs) are successfully synthesized through a facile one-step reduction process with atomically isolated Ir atoms anchored on an NiFe-based core. By taking advantage of their unique structure and composition, the resultant NiFeIr_x/Ni NW@NSs have a high electrocatalytic activity for OER which can deliver current densities of 10 and 100 mA cm^-2 at overpotentials as low as 200 and 250 mV in 1 M KOH, respectively. It is worth noting that NiFeIr_x/Ni NW@NSs exhibit outstanding long-term stability over 12 h at a current density of 10 mA cm^-2. Theoretical calculations also reveal that the intrinsic activity of the resultant NiFeIr_x/Ni NW@NSs is significantly enhanced upon the addition of Ir single atoms, highlighting the critical role of the synergistic effect between Ir single atoms and the support. Due to their easy synthesis and superior electrochemical performance, the newly designed nanostructures may find promising potential applications in water splitting and other related fields. © 2019 American Chemical Society.