Chemical reactivity and variation in electronical properties of graphene on Ni(111) and reduced graphene oxide

In this chapter I will describe the chemical reactivity and the electronical properties variation of graphene (G) supported on Ni(111) and of the reduced Graphene Oxide (rGO). The reason behind this double choice is to give a complete overview of this innovative material from the fundamental point of view and more applicative studies. These researchers were developed in the framework of University of Genoa, Polytechnic of Turin and Istituto Italiano di Tecnologia, Center for Space Human Robotic IIT@PoliTo (Italy). 1) In the first part of this chapter I will present the main results obtained on the reactivity, towards CO, of pristine graphene grown on Ni(111). Single layer graphene films are grown by ethene dehydrogenation on Nickel, under different experimental conditions, and the system is studied in-situ by X-ray Photoelectron and High Resolution Electron Energy Loss Spectroscopies, before and after CO exposure at 87 K and at room temperature. The main results were: - the best CO reactivity in the top-fcc configuration1,2 of graphene on Ni(111), at low temperature3. - the higher reactivity occurs in the case of minimum percentage of contaminant or Ni2C still present during the grown process2. The second step consists in modifying the pristine graphene, which is inert at room temperature, inducing punctual defects, by controlled sputtering. I obtained an unexpected reactivity toward CO also at room temperature, with possible applications e.g., gas sensing4,5 2) In the second part of the chapter I will be describe more applicative aspect of GO and rGO systems developed previously at Polytechnic of Turin and IIT@PoliTo. Modifying this material, during the reduction, I studied the possibility to improve his electrical properties opening possible application in the ink-jet printing mechanism as conductive printing system6, or in the functionalization of graphene7. In particular the surface modification of GO, by two steps Ultraviolet (UV) based process, allowed to improve the dispersion of GO in organic solvent and polymeric matrix. This process results particular appealing for instance in the fabrication of printable inks and coatings. Finally, I will explain the use of rGO membranes for one daily application regarding the desalinization process of water.