## 3 Results and Discussion
This shift is due to the surface shielding effects, since the inner shell of H\({}_{2}\)O is more effectively shielded by surface electrons than by the electrons of H\({}_{2}\)O molecule itself. In the XPS spectra of a water molecule adsorbed on a metal surface, two O 1s peaks at BEs of \(\sim\)532.5 eV (H\({}_{2}\)O) and \(\sim\)531 eV (hydroxyl groups) are usually observed [46]. The presence of bound hydroxyl groups enhances water binding [45], as the H\({}_{2}\)O-OH H-bonding is stronger than the H\({}_{2}\)O-H\({}_{2}\)O H-bonding. Thus, two O 1s peaks with BE of 530.8 eV and 532.4 eV were observed for Cu (110) [45] and at 530.8-532.3 eV for Ru [47]. Moreover, the formation of a H\({}_{2}\)O bilayer was observed on the surface of metal [48], graphene [49] and fullerite C\({}_{60}\)[40] under vacuum of 10\({}^{-9}\) torr. Thus, a comparison of our XPS data with the results of other studies suggests that the low-energy component (530.6 eV) of the O 1s XPS spectrum of C\({}_{60}\) is associated with hydroxyl groups, and the 532.1 eV line is associated with H\({}_{2}\)O from the surface layer of water. The HOPG O 1s XPS spectrum contains one peak at 532.0 eV, which can be also associated with adsorbed water. The C 1s photoelectron spectrum of MWCNTs (Figure 4b) is composed of four bands: the high intensity peak A at photon energy of 284.5 eV (corresponding to BE of carbon atoms in graphite), the two bands--286.4 eV and 287.6 eV (corresponding to BE of carbon atoms singly and doubly bonded to oxygen atoms, respectively) and 290.8 eV band--a \(\pi\)-plasmon satellite of the C 1s line in aromatic compounds. The O 1s XPS spectrum of MWCNTs was fitted by two peaks (Figure 4c) with O1s BEs of 531.7 eV and 533.5 eV, assigned to of the oxygen atom in the C=O and C-O functional groups, respectively [50]. However, taking into account the previous analysis of the C\({}_{60}\) and HOPG spectra, the peak at BE of 531.7 eV in the O 1s spectrum of MWCNTs should be associated with adsorbed water molecules. The situation changes for the C 1s and O 1s XPS spectra of the CSS, as shown in Figure 4b,c. The C 1s XPS spectrum of the CSS is composed of three bands. The band A at BE of 284.5 eV corresponds to carbon atoms in turbostatic graphite, the band at BE of 286.4 eV is connected with the presence of carbon atoms singly bonded to oxygen atoms (C-O) in MWCNT, and the band with BE of 287.6 eV represents the signal from carbon atoms doubly bonded to oxygen atoms (C=O). This identification is according to C 1s NEXAFS data. The O 1s spectrum is composed of three bands at BEs of 530.6 eV, 531.8 eV and 533.0 eV. The O 1s BEs of many compounds fall within a very narrow range, resulting in overlap of a large number of certain spectral components. The CSS C 1s NEXAFS spectrum contains the high energy peak (\(\sim\)532 eV) associated with C-O, C-O-C, C=O bonds and anion [CO\({}_{3}\)]\({}^{2}\). Moreover, oxygen will always be present at surfaces exposed to the atmosphere due to water adsorption. Therefore, the low-energy peaks in the O 1s spectrum of CSS, as in the case of the fullerite C\({}_{60}\), are associated with hydroxyl groups (530.6 eV) and with H\({}_{2}\)O from the surface water layer (531.8 eV). The water presence on the CSS surface (\(\sim\)5-6 at.%) compared to C\({}_{60}\), HOPG and MWCNT (\(\sim\)2 at.%) is probably due to high roughness and specific area of its surface due to the formation of abundant nanopores [13].