Effects of Electron Irradiation on the Absorptivity of Reduced Graphene Oxide Characterized by Fourier Transform Infrared Spectroscopy (FTIR)*

We study the effects of electron beam irradiation of reduced graphene oxide (rGO) on its absorptivity using Fourier transform infrared (FTIR) spectroscopy.  Previous research of graphene after electron irradiation and examined using Raman Spectroscopy has provided evidence for sp3-type defects in its structure, many of which are associated with hydrogen atom attachment. Yet, due to its high oxygen content, its feasibility to be used as a storage vehicle is restricted. Therefore, we are investigating the properties of rGO after electron irradiation as a viable candidate for hydrogenation, having undergone a chemical reduction to remove many of its functional groups. Due to its ability to retain residual defect sites created during the reduction process, rGO can serve as a reactive site for hydrogen attachment. rGO powder was irradiated with electrons in an ultra-high vacuum using a current of 2 to 2.5 nA and a dosage of 3 × 1017 electrons/cm2 and analyzed using FTIR. From FTIR, we noted three absorption peaks around 775, 896 and 969 cm-1, and an additional -OH functional group that intensifies around 3500 cm⁻¹. This suggests that irradiated rGO undergoes partial reoxidation, reforming oxygenated groups and functionalities. The source of the other peaks is under investigation and will be discussed.