Iron, rhodium-codoped NiP nanosheets arrays supported on nickel foam as an efficient bifunctional electrocatalyst for overall water splitting.

To enhance the overall water splitting efficiency, it is widely attractive yet challenging to develop low price, abundance and efficient bifunctional electrocatalysts towards oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). Herein, Fe,Rh-codoped NiP nanosheets arrays were in situ anchored on three-dimension (3D) Ni foam under hydrothermal condition and successive phosphorization, denoted as Fe,Rh-NiP/NF for simplicity. The unique nanosheets arrays effectively enriched the active sites with easy accessibility. By virtue of the unique sheet-like arrays and 3D porous conductive substrate, the prepared Fe,Rh-NiP/NF showed the low overpotentials of 226 mV at 30 mA cm towards the OER and 73 mV at 10 mA cm for the HER. Moreover, the electrocatalyst effectively worked as anode and cathode for overall water splitting system, showing a small voltage of 1.62 V to drive a current density of 10 mA cm. The present work provides alternative option for fabricating advanced catalysts in electrocatalysis and energy devices.