The Effect of Gamma Irradiation on the Subsequent Thermal Reduction of Graphene Oxide Aerogel Monoliths

Abstract Graphene oxide aerogel (GOA) monoliths pre-treated with 60Co gamma rays (doses of 20–220 kGy) were annealed in an inert gas flow (He, 300°C, 4 h). IR and XPS spectroscopy revealed that gamma irradiation and subsequent annealing resulted in partial reduction of GOA: the amount of labile hydroxyl and epoxy groups decreased and that of carbonyl and ester groups were preserved. The degree of GOA reduction during the described treatments decreased with increasing irradiation dose. It is likely that the thermal stability of oxygen-containing functional groups on the GO sheet surface increases with increasing radiation dose. Gamma irradiation also resulted in a decrease in the specific surface area of annealed GOA due to a decrease in the proportion of micropores and an increase in the proportion of mesopores. These changes are stable, opening up prospects for fine-tuning the properties of GOA (such as specific surface area, hydrophilicity, and sorption capacity) for specific applications in catalysis, sorption, composite fabrication, and energy-saving systems.