Synthesis of Iron–Nickel Sulfide Porous Nanosheets via a Chemical Etching/Anion Exchange Method for Efficient Oxygen Evolution Reaction in Alkaline Media

Abstract

Abstract The development of high‐efficient and cost‐effective catalytic electrodes for oxygen evolution reaction (OER) is highly desirable. Herein, interpenetrated porous 3D‐networked iron–nickel sulfide nanosheets are synthesized on nickel foam (NF) (donated as FeS–Ni 3 S 2 /NF) via partial chemical etching of Ni(OH) 2 /NF precursor with Fe(CN) 6 3− , followed by chemical etching/anion exchanging of Fe(CN) 6 3− and OH − with S 2− . The resulting FeS–Ni 3 S 2 /NF nanosheets possess a remarkable catalytic activity for the OER with overpotentials of only 238 and 290 mV at 10 and 100 mA cm −2 , respectively, much lower than Ni 3 S 2 /NF. Furthermore, the catalyst exhibits the low Tafel slope (44 mV dec −1 ) and outstanding OER stability. This work provides a simple way for fabricating highly efficient electrocatalysts toward OER.