Synchrotron Radiation Soft X-ray Induced Reduction in Graphene Oxide Characterized by Time-Resolved Photoelectron Spectroscopy

Synchrotron radiation soft X-ray was employed to reduce graphene oxide (GO) films in ultrahigh vacuum. The dissociation of oxygen-containing functional groups, and the formation of sp2 C–C bonds were revealed by time-resolved in situ X-ray photoelectron spectroscopy, demonstrating the X-ray reduction of GO. The number of C–O bonds of GO exhibited an exponential decay with exposure time. The X-ray reduction rate of GO was positively correlated with the intensity of low-energy secondary electrons excited from substrates by soft X-ray, indicating the C–O bonds were dissociated by secondary electrons.