Nanocasting synthesis of an iron nitride-ordered mesopore carbon composite as a novel electrode material for supercapacitors

Abstract

Herein, a series of novel iron nitride (Fe₂N)/cubic-ordered mesoporous carbon (OMC) composites (Fe₂N@OMC) were synthesized via a facile nanocasting route and ammonia calcination. Physical characterization results indicate that small non-aggregated Fe₂N nanoparticles were evenly distributed on the external surface and in the pores of the carbon material with a linear array of mesopores in a regular interval arrangement. An electrochemical test was carried out using Fe₂N@OMC as a negative electrode of a supercapacitor in 6 mol L⁻¹ KOH aqueous electrolytes. The results indicated that the obtained Fe₂N@OMC-2 exhibited a superior specific capacitance of 547 F g⁻¹ at 1 mV s⁻¹ and 520 F g⁻¹ at 0.5 A g⁻¹, an excellent rate capability (398 F g⁻¹ at 20 A g⁻¹ with capacitance retention of 76%), and an outstanding cycling stability. After 1000 cycles, the specific capacitance retention of Fe₂N@OMC-2 remained 85%, which was much higher than 28% of the bare Fe₂N.