XPS analysis of the GO based materials

Graphene oxides samples were measured by XPS method. The X-ray photoemission spectroscopy measurements were carried out with Omicron NanoTechnology UHV equipment. The hemispherical spectrophotometer was equipped with a 128-channel collector. The XPS measurements were performed at room temperature at a pressure below 1.1 × 10−8 mBar. The photoelectrons were excited by an Mg-Kα X-Ray source. The X-ray anode was operated at 15 keV and 300 W. Obtained results were analyzed by Xasa XPS software. For measurements powders of the pure graphene oxide (GO), reduced graphene oxide (rGO) and functionalized by S and N elements graphene oxide were selected. Nitrogen doped graphene oxide was synthesized by the hydrothermal method.