Low-Temperature Plasma-Assisted Synthesis of Iron and Nitrogen Co-Doped Cofep-N Nanowires for High-Efficiency Electrocatalytic Water Splitting

The water splitting catalytic efficiency is determined by interactions between the multiple main constituent elements and dopants. However, achieving performance-boosting synergistic interactions between different species in the catalyst is challenging. This work demonstrates such effect using low-temperature plasma-enhanced hydrothermal-phosphorization synthesis of Fe, N co-doped CoFeP-N nanowires. The produced CoFeP-N nanowires exhibit far superior hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) activities in an alkaline medium compared to the original CoP, with overpotentials of 64 mV and 218 mV at 10 mA cm-2 respectively, and excellent cycling stability. When CoFeP-N is used as a two-electrode water splitting device, a low voltage of only 1.636 V was needed to achieve a current density of 100 mA cm-2, which is better than that of Pt/C||RuO2 and most non-precious metal-based electrocatalysts reported to date. These experimental results provide new insights and strategies for developing efficient, stable, and low-cost bifunctional water splitting electrocatalysts.