Self-Assembly of Ni–Fe Layered Double Hydroxide on Fe Foam as 3D Integrated Electrocatalysts for Oxygen Evolution: Dependence of the Catalytic Performance on Anions under in Situ Condition

Herein, we demonstrate a very facile self-assembly method to fabricate a Ni–Fe layered double hydroxide (LDH) 3D integrated film at ambient temperature without energy input as a highly efficient electrocatalyst for oxygen evolution reaction (OER). By this method, we can readily regulate the Ni–Fe proportion and change the embedded guest anions into the LDH under our in situ synthetic condition by just using different nickel salts to prepare Ni–Fe LDH. It is found that the Ni–Fe ratio and the embedded guest anions can dramatically influence the corresponding OER catalytic performance. An excellent OER activity that delivering overpotentials of about 210 and 240 mV to reach 10 and 100 mA cm–2 current densities in 1.0 M KOH was achieved.