N-doped FeP nanorods derived from Fe-MOFs as bifunctional electrocatalysts for overall water splitting

The nonprecious metal-based electrocatalysts with high activity and low cost is the key factors for renewable energy conversion by electrocatalytic water-splitting. Herein, we have designed nitrogen-doped FeP nanorods (N-FeP) derived from metal-organic frameworks (MOFs) through continuous phosphorization and thermal decomposition. Notably, P atoms can effectively grab electrons from Fe atoms and serve as the base to trap protons, bringing more active sites. Moreover, the bond strength between FeP and oxygen (O) can be properly modified by introducing a small amount of N into FeP, causing the expedited oxygen evolution. The obtained N-doped FeP electrocatalyst exhibits 226 mV and 440 mV at 10 and 100 mA cm−2 for the HER and OER in alkaline solution, respectively. Further, electrochemical water splitting has been achieved with 100 mA cm−2 at a low overpotential of 490 mV. Therefore, this work gives inspiration for the construction and modification of transition metal phosphides for water splitting.