Understanding the growth N–Fe3C from assembly of carbon-coated iron nanoparticles on rGO as efficient oxygen reduction electrocatalysts

The oxygen reduction reaction (ORR) is an essential reaction in metal-air battery systems. However, the traditional noble metal Pt-based catalysts for ORR limit the commercial applications of air battery systems due to their high price, low abundance and poor tolerance. In recent studies, nitrogen–doped transition metal carbides have shown promise as an alternative to traditional noble metal catalysts. In this paper, the thermal cracking and calcination method was used to successfully obtain the growth N-doped carbon coated iron carbide nanoparticles (Fe3C@NC/rGOx NP) from assembly of carbon-coated iron oxide Nano-crystals on rGO (Fe3O4@NC/rGOx NCs). Transmission electron and scanning electron microscopy of the fabricated specimens indicated the presence of many carbon shells and pores in the etched samples. The electrochemical test results of the fabricated specimens suggested that the Fe3C@NC/rGO 100 NP annealed at 800 °C exhibited a better ORR behavior than that of Pt/C in a basic electrolyte