Porous Indium Tin Oxide-Supported NiFe LDH as a Highly Active Electrocatalyst in the Oxygen Evolution Reaction and Flexible Zinc–Air Batteries

The oxygen evolution reaction (OER) is crucial for hydrogen production from water splitting and rechargeable metal–air batteries. However, the four-electron mechanism results in slow reaction kinetics, which needed to be accelerated by efficient catalysts. Herein, a hybrid catalyst of novel nickel–iron layered double hydroxide (NiFe LDH) on porous indium tin oxide (ITO) is presented to lower the overpotential of the OER. The as-prepared NiFe LDH@ITO catalyst showed superior catalytic activity toward the OER with an overpotential of only 240 mV at a current density of 10 mA/cm2. The catalyst also offered high stability with almost no activity decay after more than 200 h of chronopotentiometry test. Furthermore, the applications of NiFe LDH@ITO in (flexible) rechargeable zinc–air batteries exhibited a better performance than commercial RuO2 and can remain stable in cycling tests. It is supposed that the superior catalytic behavior originates from the ITO conductive framework, which prevents the agglomeration and facilitates the electron transfer during the OER process.