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

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.