A facile, green and time-saving method to prepare partially crystalline NiFe layered double hydroxide nanosheets on nickel foam for superior OER catalysis

The partially crystalline NiFe layered double hydroxide (pc-NiFe-LDH) nanosheets, as a high-efficient and cost-effective catalyst toward oxygen evolution reaction (OER), were synthesized by a facile, green and time-saving strategy in this work. The pc-NiFe-LDH can spontaneously grow in situ on the Ni foams (NF) at room temperature and does not consume any extra energy. The 3D structure of the pc-NiFe-LDH/NF with more active sites was confirmed by SEM, TEM and the calculated large electrochemical active surface area (ECSA) of 118 cm2, which endowed the pc-NiFe-LDH/NF with an outstanding OER performance in 1.0 M KOH. The overpotentials of 133 mV and 153 mV (vs. RHE, with 95% iR compensation) at the current density of 20 mA cm−2 and 100 mA cm−2 were obtained, respectively. The pc-NiFe-LDH/NF showed rapid OER kinetics and efficient mass and electron transfer with a small Tafel slope of 30 mV dec−1, and excellent endurance for 17 h long-term continuous OER operation at 1.609 V (vs. RHE, without iR correction) with 2.6% enhancement of the current density. The performance was superior to those of most reported NiFe-based catalysts, which made it grand feasibility in practical industrial applications.