Electron-irradiation-induced reinforcement of reduced graphene oxide papers

Here we show that the graphene sheets in reduced graphene oxide papers (rGOPs) can be cross-linked by electron-irradiation-induced sp3 carbon atoms, resulting in significant enhancements in both the mechanical and electrical properties compared to unirradiated rGOPs. We find that the residual oxygen-containing functional groups in rGOPs are removed during irradiation. We also observe that the Wigner energy release temperature in rGOPs is 102–188 °C, which is lower than that (∼200 °C) in pure graphite. The mechanisms to form sp3 cross-links and the evolutions of sp3 carbon atoms under irradiation are revealed through molecular dynamics simulations.