Surface-modified amorphous FeOOH on NiFe LDHs for high efficiency electrocatalytic oxygen evolution

Electrochemical water splitting provides a promising pathway to produce hydrogen, but the oxygen evolution reaction (OER) with sluggish kinetics is the bottleneck. The design and synthesis of high efficiency catalysts is the key to overcome the OER barrier. Herein, the surface-modified amorphous FeOOH on NiFe LDHs (FeOOH-a@NiFe LDHs) was synthesized by using a simple hydrothermal and electrodeposition method. The amorphous FeOOH on NiFe LDHs can provide more active sites for the adsorption and activation of *H2O and facilitate the interfacial electron transfer, which significantly accelerates the OER kinetics. The FeOOH-a@NiFe LDHs show low overpotentials of 237 mV and 252 mV to achieve 50 mA cm−2 and 100 mA cm−2 respectively, and the activity maintains above 90% after long-term testing at a high current density of 100 mA cm−2 for 500 h. Moreover, the water electrolysis device with the FeOOH-a@NiFe LDHs‖Pt/C(20%) as electrode requires only a low cell votage of 1.48 V to achieve 10 mA cm−2. This work provides an efficient OER catalyst which could serve as a potential catalyst for industrial electrocatalytic water splitting.