Bifunctional Ni-Fe/NiMoNx nanosheets on Ni foam for high-efficiency and durable overall water splitting

Fabricating bifunctional electrocatalysts for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is challengeable. Herein, an efficient and durable bifunctional Ni-Fe/NiMoNx electrocatalyst has been synthesized on nickel foam. This electrocatalytic system exhibits significant HER and OER performances with overpotentials of 49 and 260 mV at 20 mA cm−2, respectively. For overall water splitting, Ni-Fe/NiMoNx electrodes require only 1.54 V for 10 mA cm−2. This enhanced HER and OER electrocatalytic performance is due to the combined effect of multiple active components formed after NH3 treatment. This work provides a new strategy for the rational design of bifunctional electrocatalysts for overall water splitting.