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. [Display omitted] •Bifunctional Ni-Fe/NiMoNx nanosheets electrocatalyst is facilely designed and synthesized.•The incomplete nitridation during NH3 treatment significantly enhances electrocatalytic performance for both HER and OER.•Nickel foam is transformed into active components, which achieves the rational utilization of NF.