In‐situ Surface‐selective Removal of Al Element from NiFeAl Ternary Nanowires for Large‐current Oxygen Evolution Reaction

Abstract To store renewable energy via water splitting, it is crucial to design low‐cost and high‐performance catalysts for oxygen evolution reaction (OER). In this work, a ternary nanowire supported on nickel foam (NiFeAl‐NW/NF) with high specific surface area and catalytic activity was prepared by hydrothermal method and in‐situ selective surface removal. High OER current densities of 100, 500 and 1000 mA ⋅ cm⁻² were achieved under anode potentials of 1.52, 1.56 and 1.60 V vs. RHE, respectively. The NiFeAl‐NW/NF was stable under 1 A cm⁻² OER current density in the 40 hour durability test. In situ surface selective removal of aluminum from nanowires provides abundant structural defects, which effectively enlarge the electrochemically surface area of the integral catalyst suitable for large‐current oxygen evolution reaction (OER).