Siva Kumar Ramesh1,Jihye Son1,Vinoth Ganesan2,Jinkwon Kim1
Kongju National University1,Kumoh National Institute of Technology2
Siva Kumar Ramesh1,Jihye Son1,Vinoth Ganesan2,Jinkwon Kim1
Kongju National University1,Kumoh National Institute of Technology2
The rational design of transition metal-based hollow nanostructures is critical for improving hydrogen production efficiency through water electrolysis and rechargeable metal-air batteries. In this study, a self-templating approach is reported to synthesize carbon-incorporated Ni<sub>2</sub>P-Fe<sub>2</sub>P hollow nanorods ((Ni,Fe)<sub>2</sub>P/C HNRs) as efficient oxygen evolution reaction (OER) in alkaline solutions. First, a Ni<sub>2</sub>(BDC)<sub>2</sub>(DABCO)-MOF (Ni-MOF) is converted to NiFe-PBA hollow nanorods (HNRs) by anion ion exchange, followed by a subsequent phosphidation process to construct (Ni,Fe)<sub>2</sub>P/C HNRs. Benefiting from the synergetic effect of heterostructure phosphide composition and unique hollow rod morphology, (Ni,Fe)<sub>2</sub>P/C HNRs have a high specific surface area and superior electrocatalytic OER performance. The as-prepared (Ni,Fe)<sub>2</sub>P/C HNRs exhibit OER performance with a small overpotential of 258 mV to reach a current density of 10 mA cm<sup>-2</sup>, a small Tafel slope of 45.5 mV dec<sup>-1</sup>, and long-term stability for 40 h, which significantly outperforms the (Ni,Fe)<sub>2</sub>P/C NPs and commercial RuO<sub>2</sub>. Post-XPS and SEM measurement of (Ni,Fe)<sub>2</sub>P/C NPs indicates the robust nature of the catalyst.