High electrocatalytic performance of Fe3C-encapsulated N-doped carbon nanotubes and nanosheets for oxygen reduction reaction

The different morphologies of iron carbide encapsulated nitrogen-doped carbon nanotube and nanosheet (Fe3[email protected], Fe3[email protected]) electrocatalysts were synthesized by a one-step calcination method. They were used as electrocatalysts for the oxygen reduction reaction. The electrochemical measurement results indicated that the half-wave potentials (E1/2) on the Fe3[email protected] and Fe3[email protected] glassy carbon electrodes reached 0.845 V and 0.860 V, respectively. Compared with 20 wt% commercial Pt/C (0.856 V), the E1/2 on the Fe3[email protected]/GCE shifted positively. The onset potentials (Eonset) on the Fe3[email protected] was 1.056 V, which was higher than that on commercial Pt/C (0.998 V) and Fe3[email protected] (0.996 V). The Fe3[email protected] showed a better electrocatalytic property toward ORR than Fe3[email protected], which results from the Fe3[email protected] (735.58 m2 g−1) with a larger specific surface area than that of Fe3[email protected] (191.20 m2 g−1). The stability of the Fe3[email protected] was better than that of the Fe3[email protected] contribution to the Fe3C particles encapsulated by the carbon nanotubes.