Corrosion Engineering towards NiFe‐Layered Double Hydroxide Macroporous Arrays with Enhanced Activity and Stability for Oxygen Evolution Reaction

Abstract NiFe‐layered double hydroxide (NiFe‐LDH) is the benchmark catalyst for the oxygen evolution reaction (OER) in alkaline medium, however, it is still challenging to improve its activity and stability. Herein, NiFe‐LDH macroporous array electrodes are demonstrated to significantly enhance the activity and stability for oxygen evolution reaction. The electrodes are fabricated by the chemical and electrochemical corrosion process of Ni foam induced by ferric nitrate, hydrochloric acid and oxygen. By optimizing the amount of iron salt and acid and selecting the appropriate reaction temperature and time, the NiFe‐LDH electrodes only need the overpotential of 180 mV and 248 mV to reach the current density of 10 mA cm −2 and 500 mA cm −2 , respectively, and remain highly stable for 1000 h at 500 mA cm −2 . The unique macroporous array not only significantly increases the active area of NiFe‐LDH catalyst, but also creates a stable nanostructure that avoids severe reconstruction.