XPS C1s spectra of Graphite and Graphene oxide
XPS spectra were obtained in a Kratos Axis Ultra DLD irradiating the samples with an Al monochromatic Kα radiation of energy (1486.6 eV) at a power of 150 W. C1s high resolution spectras of all samples were performed with pass energy of 20 eV. ). In the Graphite spectra, we can see the main peak corresponding to the sp2 carbon, two other peaks related to the sp3 carbons and to the hydroxyl group, and a band corresponding to the shake-up satellite π-π*, typical of aromatic bonds. For GO samples, two convoluted peaks appeared in the principal spectra, centered at 284.76 and 286.78. The deconvolution of these peaks reveals one peak of sp2 carbon, one peak of sp3 carbon, four peaks of oxidized carbons groups (hydroxyl, epoxy, carbonyl, and carboxyl) and one peak of shake-up satellite (plasmon π-π*).