Nanoarchitectonics tuning for Fe/N-doped C60-derived carbon electrocatalysts with enhanced ORR activity by oxygen plasma treatment on C60

Abstract

Due to designable chemical modifications and self-assembly structures, fullerenes have enabled an innovative platform for controlling the configuration of heteroatoms in carbon structures and improving the catalytic activity of metal–N–C systems. In most cases, the Fe–N doping in fullerene-derived carbons was achieved based on the coordination interactions of Fe species with N-containing groups. In this study, we tried to enhance the binding of Fe ions by the control oxidation of C₆₀s via facile O₂-plasma treatment. The strong interactions between Fe and oxidized C₆₀s enable higher Fe doping content and promote the formation of FeN_x sites during pyrolysis under NH₃. The resultant FeN/C₆₀O-900 electrode showed excellent electrocatalytic activity and high stability in the oxygen reduction reaction (ORR), surpassing the commercial Pt/C (20 wt%) catalyst and other Fe/N-doped fullerene-derived carbons. The structural analysis and simulations revealed that the presence of oxygen near FeN_x can enhance the ORR activity. This study is likely the first example of driven Fe–N doping from the oxidation of C₆₀ carbons. It might provide new insight into controlling heteroatom doping in C₆₀-derived electrodes.