Palladium Modified FeCoS2 Nanosheet Arrays on Ni Foam as Bifunctional Electrodes for Overall Alkaline Water Splitting

Abstract The development of high‐efficient electrocatalysts with low applied voltage and robust stability is of great importance for electrolysis of water. In this work, a bifunctional electrode has been developed by growing palladium‐modified FeCoS 2 nanosheet arrays on Ni foam (Pd‐FeCoS 2 NAs/NF), which can serve as anode and cathode for alkaline water splitting with high activities and ultra‐strong durability. The Pd‐FeCoS 2 NAs/NF shows overpotentials of 130 mV for hydrogen evolution reaction (HER) and 202 mV for alkaline oxygen evolution reaction (OER) at 10 mA cm −2 . The alkaline electrolyzer is built by employing Pd‐FeCoS 2 NAs/NF as cathode and anode, delivering a current density of 50 mA cm −2 at 1.59 V. Moreover, the electrolyzer can run stably for 600 h with negligible decline.