Substrate-Dependent Oxygen Evolution Performance of Electrodeposited CoNiFe Layered Double Hydroxide: Nickel Fiber Film as an Optimal Support

Abstract

Efficient alkaline water electrolysis requires earth-abundant oxygen evolution reaction (OER) electrocatalysts that combine low overpotential, rapid kinetics, and operational durability. Herein, trimetallic CoNiFe layered double hydroxide (LDH) was grown directly on nickel fiber film (NFF) by a simple one-step electrodeposition method and evaluated across multiple conductive substrates. The optimized CoNiFe LDH/NFF electrode delivered superior OER activity in 1.0 M KOH, requiring overpotentials of only 241 and 306 mV to reach 10 and 50 mA cm−2, respectively, with a Tafel slope of 66.15 mV dec−1. Electrochemical impedance analysis confirmed low series and charge-transfer resistances, while chronopotentiometry demonstrated stable operation for 24 h with 99.61% potential retention at 20 mA cm−2. The improved performance arises from the conductive porous NFF scaffold, homogeneous trimetallic LDH nanosheets, and in situ formation of active oxyhydroxide species. These results establish CoNiFe LDH/NFF as a promising binder-free anode for efficient alkaline water electrolysis.