Fe–Fe₃C Functionalized Few-Layer Graphene Sheet Nanocomposites for an Efficient Electrocatalyst of the Oxygen Reduction Reaction

Abstract

Preparation of a high-efficiency, low-cost, and environmentally friendly non-precious metal catalyst for the oxygen reduction reaction (ORR) is highly desirable in fuel cells. Herein, a Fe–Fe3C-functionalized few-layer graphene sheet (Fe/Fe3C/FLG) nanocomposite was fabricated through the vacuum heat treatment technique using ferric nitrate and glucose as the precursors and exhibited a high-performance ORR electrocatalyst. Multiple characterizations confirm that the nanosized Fe particles with the Fe3C interface are uniformly distributed in the FLGs. Electrocatalytic kinetics investigation of the nanocomposite indicates that the electron transfer process is a four-electron pathway. The formation of the Fe3C interface between the Fe nanoparticles and FLGs may promote the electron transfer from the Fe to FLGs. Furthermore, the Fe/Fe3C/FLG nanocomposite not only exhibits high ORR catalytic activity but also displays desirable stability. Consequently, the obtained Fe/Fe3C/FLG nanocomposite might be a promising non-precious, cheap, and high-efficiency catalyst for fuel cells.