Carbon-incorporated Ni2P-Fe2P hollow nanorods as superior electrocatalysts for the oxygen evolution reaction.

A rational design and cost-effective transition metal-based hollow nanostructures are important for sustainable energy materials with high efficiency. This study reports on carbon-incorporated Ni2P-Fe2P hollow nanorods ((Ni,Fe)2P/C HNRs) derived from a self-template approach as efficient electrocatalysts. Initially, a Ni2(BDC)2(DABCO)-MOF (Ni-MOF) is converted to NiFe-PBA hollow nanorods (HNRs) through facile ion exchange which was further converted to (Ni,Fe)2P/C HNRs via a subsequent phosphidation process. The resulting (Ni,Fe)2P/C HNRs exhibit remarkable activity for the oxygen evolution reaction in an alkaline solution requiring a small overpotential of 258 mV to drive a current density of 10 mA cm-2 and long-term stability with little deactivation after 40 h. (Ni,Fe)2P/C HNRs outperform (Ni,Fe)2P/C NPs and commercial RuO2. The unique hollow morphology and interfacial electronic structure substantially increase the active site and charge transfer rate of our electrocatalyst, resulting in excellent OER activity and stability.