Industrially promising IrNi-FeNi3 hybrid nanosheets for overall water splitting catalysis at large current density

This work reports an industrially promising catalyst with ultralow Ir-loading, highly activity and stability for overall water splitting at large current density. [Display omitted] •IrNi-FeNi3 hybrid nanosheets are prepared by hydrothermal method.•It needs ultralow overpotentials for OER (η20 = 240.0 mV) and HER (η10 = 31.1 mV).•Only 1.47 V is needed to arrive at 10 mA cm−2 for overall water splitting.•For OER and HER, it can maintain at +1000 mA cm−2 for 124 h.•It also can maintain at 500 mA cm−2 for 100 h in 6.0 M KOH at 60 ℃. Preparing efficient and stable catalysts is one of the most urgent problems for water splitting. Herein, IrNi-FeNi3 hybrid self-supported on nickel foam with unique nanosheets and 1.218 wt.% Ir-loading is synthesized via hydrothermal method. In 1.0 M KOH, ultralow overpotentials for oxygen evolution reaction (OER, η20 = 240.0 mV, η1000 = 330.0 mV) and hydrogen evolution reaction (HER, η10 = 31.1 mV, η1000 = 288.8 mV) are needed. Only 1.47 V is required for overall water splitting to arrive at 10 mA cm−2, indicating superior activity. For overall water splitting, it also demonstrates good stability with negligible declines after testing for 100 h at 500 mA cm−2 in 6.0 M KOH at 60 ℃, which is close to the practical application. The unique self-supported nanosheets structure on nickel foam can expose more active sites and the hybridization of IrNi with FeNi3 can promote the intrinsic activity of catalyst. Therefore, this work proposes an industrially promising catalyst for water splitting.