A Dual-Function Fe-Doped Co3O4 Nanosheet Array for Efficient OER and HER in an Alkaline Medium

The electrocatalysts of heteroatom-doped non-precious metal oxide materials are of great significance for efficient and low-cost electrochemical water-splitting systems. Herein, an innovative Fe-doped Co3O4 nanoflake (Fe-Co3O4/NF) on nickel foam has been developed, which exhibits excellent electrocatalytic activity for both hydrogen evolution reactions (HERs) and oxygen evolution reactions (OERs). Benefiting from the synergy of the charge redistribution and d-band center shift caused by doping engineering, the as-obtained Fe-Co3O4/NF shows both excellent HER (η10 = 196 mV) and OER (η10 = 290 mV) activities with low Tafel slopes (109 mV dec−1 for HER and 49 mV dec−1 for OER, respectively) and excellent stability. This work provides an effective method for designing and synthesizing bifunctional electrocatalysts with high activity and stability of metal oxide hybrids for the HER/OER.