In-situ construction of electrodeposited polyaniline/nickel-iron oxyhydroxide stabilized on nickel foam for efficient oxygen evolution reaction at high current densities

We report an in-situ construction method for the NiFe-based oxyhydroxide OER electro-catalyst supported on the nickel foam (NF) substrate with the polyaniline (PANI) interlayer by sequential electrochemical deposition steps (NF/PANI/NiFe-OH). The ultra-thin nano -sheet for the nickel-iron (oxy)hydroxides tightly grown on the porous PANI exhibits the enhanced electrochemical characteristics associated with the promotion roles of the PANI layer, which increases the number of active sites, facilitates the charge transfer, and ac-celerates water transport across the interfaces of the electrode. The as-prepared NF/PANI/ NiFe-OH has reliable lower overpotentials of 260, 340, and 490 mV without iR-correction at 50, 100, and 200 mA cm-2 of high current densities, respectively. The smaller Tafel slope, larger ECSA, and TOF values of the electrode reveal its high intrinsic activity. Moreover, the electrode shows good stability and durability without the damage of morphology, change of surface chemical state, and substantial loss of active components at high current density.(c) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.