The optimized interfacial connection of graphene sheets is the key challenge of extending the unique intrinsic properties of nanoscale sheets to macroscopic films.Functional groups decorating defects, expected to be predominantly sheet edges of the graphene, are shown to transfer forces to the in-plane carbon-carbon bonding using a novel technique combining atomic force microscopy (AFM) to mechanically deform materials while synchrotron Fouriertransform infra-red (FTIR) micro-spectroscopy evaluated molecular level bond deformation mechanisms of graphene film.The shifts of functional groups fingerprint peaks reveal that forces were transferred between both C=C and C=O bonds during tensile deformation.Moreover, nitrogen/sulfur-codoped hierarchical porous graphene-based metal-free catalyst has been facilely prepared from Fe-oleate precursor intercalated between graphene sheets via a solventless thermal decomposition method.Electrochemical characterizations indicate that the synthesized nanomaterial has outstanding performance toward ORR in an alkaline electrolyte,including comparable onset potential with commercial Pt-C, large kinetic-limiting current density, a four-electron catalytic pathway and high yield, which are important to make this graphene-based catalyst a valuable candidate for practical fuel cell applications.