Structural and chemical modifications of graphene oxide induced by high-energy electron beam irradiation

Electron beam irradiation has emerged as a powerful technique for modifying material properties at the atomic level, offering vast potential for advanced applications in nanotechnology and material science. This study investigates the impact of electron beam irradiation on graphene oxide (GO) thin films, focusing on structural, chemical, and electrical modifications. GO was synthesized using Hummer’s method. GO solution was drop-casted onto ITO substrate and dried. The GO thin film was then irradiated at varying doses (25 kGy to 200 kGy) using 3 MeV electron beam. Characterization was made using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy with energy-dispersive X-ray (SEM EDX), x-ray photoelectron spectroscopy (XPS), and conductive atomic force microscopy (C-AFM). XRD analysis indicated notable changes in crystallinity, pointing to structural rearrangements induced by irradiation. At the 175 kGy dose, the irradiated graphene oxide achieved the best conductivity, and the C-AFM analysis showed a particle size of approximately 9.5 nm. The XPS and EDX analyses revealed a 0.81% reduction in oxygen concentration at an irradiation GO of 100 kGy compared to unirradiated dose. This reduction trend continues to be observable up to 175 kGy, indicating progressive deoxygenation. Among tested doses, 100 kGy appears to be the most optimal for achieving significant oxygen reduction, whereas higher doses, particularly at 175 kGy, are more favorable for enhancing the material’s conductivity. At 175 kGy, the material recorded an ideality factor of 8.92 is based on C-AFM measurements. FTIR spectra confirmed significant modifications in chemical bonding, providing evidence of functional group transformations. These findings collectively demonstrate that electron beam irradiation serves a versatile tool for tuning the physiochemical properties of GO thin films, enabling precise control over the structure and functionality. The irradiation-induced alteration of GO leads to a more conductive reduced graphene oxide (rGO) with lower oxygen content.