Source-dependent epoxide depletion in graphene oxide induced by soft X-rays and low-energy electron irradiation
Year: 2026
Type: preprint
Abstract: The chemical response of graphene oxide (GO) to ionizing radiation depends on both its oxygen-containing functional groups and the energy-deposition characteristics of the radiation source. Here, self-supported GO sheets exposed to Mg Kα (1253.6 eV) X-rays and 500 eV electrons were investigated by X-ray photoelectron spectroscopy. C 1s and O 1s spectra reveal selective depletion of epoxide (C–O–C) groups, accompanied by increases in sp 2 carbon and hydroxyl-related components, while carbonyl and carboxyl groups remain nearly unchanged upon irradiation. For both sources, epoxide depletion follows a phenomenological saturating-exponential dependence on the estimated local absorbed dose. The characteristic dose is 140 ± 10 MGy for X-rays and 2310 ± 235 MGy for electrons, although electron-induced saturation is not experimentally reached. Electrons produce apparent faster changes with exposure time because of their higher dose rate but show significantly lower dose-normalized efficiency. Under the maximum exposure conditions, the nominal local electron dose is approximately 13 times the Mg Kα dose within the adopted K–O-derived continuous-slowing-down approximation. Thus, both sources induce qualitatively similar, epoxide-selective reduction, whereas the dose-normalized response remains strongly source dependent.
Source: Research Square
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7204531013