Pyrolysis-induced synthesis of iron and nitrogen-containing carbon nanolayers modified graphdiyne nanostructure as a promising core-shell electrocatalyst for oxygen reduction reaction

Low-cost facile fabrication of highly efficient non-precious-metal catalysts to replace commercial Pt-based catalysts for oxygen reduction reaction (ORR) has attracted great attentions, because it is significant for rapid commercialization of fuel cells. Based on a fact that graphdiyne, another member of the carbon family, has not been systematically investigated as a new carbon support to ORR catalysts. We here report an effective strategy for easy synthesis of a cheap iron-nitrogen-doped carbon nanolayers wrapped around graphdiyne core-shell electrocatalyst (Fe-PANI@GD-900) for ORR from one-step pyrolysis of iron and polyaniline loaded onto graphdiyne nanocomposite at 900 °C. Electrochemical results indicate that the catalyst exhibits unexpectedly high ORR activity with onset and half-wave potentials of 1.05 V and 0.82 V (vs. RHE), while its mass activity at given potentials is lower than that of the Pt/C catalyst. Moreover, Fe-PANI@GD-900 follows a direct four-electron reduction pathway, and its long-term stability is superior to Pt/C and other graphdiyne-based catalysts previously reported in the literature. The relatively excellent ORR performance may be largely attributed to the formation of high contents of graphitic-N and FeN compounds, and the addition of graphdiyne facilitating to absolutely accelerate ORR charge transfer and fully expose more N-doped active sites on the surface.