▎ 摘　　要

Graphene coatings have been widely considered as protection layers on metal surfaces to prevent surface oxidation and corrosion in gaseous atmospheres. Here, using in-situ ambient pressure X-ray photoelectron spectroscopy we demonstrate that oxygen intercalation readily occurs at full monolayer graphene/Ru(0001) interfaces in 0.5 Torr O-2 around 150 degrees C, resulting in decoupling of the graphene overlayer from the Ru surface and oxidation of the metal surface. Moreover, oxygen intercalation has been observed even upon illumination of the graphene/Ru(0001) surface with an infrared lamp in air. These results indicate that the stability of graphene/metal interfaces under ambient conditions should be taken into consideration for future applications. (C) 2014 Elsevier B.V. All rights reserved.