Ricerc@Sapienza

There is a growing interest in functionalizing graphene (Gr), the prototype one-atom-thick two-dimensional (2D) material, in order to obtain a semiconducting 2D material with the excellent mechanical and morphological properties of graphene. A fully hydrogenated graphene mesh is called "graphane" and it is predicted to present an energy gap above 3.5 eV, maintaining the sheet properties of graphene, with a distortion of the sp2 bonds towards sp3 due to C-H bonding, whose realization would have a high impact in opto-electronic devices. Experimental achievement of "graphane" with a high H-upload and a low density of defects is still an open problem, though. Furthermore, it has been recently proposed a new high-resolution detector whose core element is tritium (T) bonded to Gr, but the manipulation of T presents severe safety limitations.

In this project we propose a new path to realize "graphane" by bonding of atomic hydrogen (H) and deuterium (D), in a very compact Gr 3D architecture, nano-porous graphene (NPG), which limits the presence of defects with respect to Gr flakes, transferred Gr etc. NPG enhances the surface-active areas ensuring a topological structure with highly connected layers, negligible density of lattice and edge defects, to engineer physical and chemical properties for the desired functionalities.

We will synthesize "graphane" by low-energy ion and hot inlet tube, at increasing H and D doses, and study it by combining x ray photoemission (XPS), Raman and IR, to determine the electronic and optical properties of 3D graphane. We will also exploit synchrotron radiation (SR) spatially-resolved photoemission at SR facilities, where the participating groups are involved in the research and development activities. We will study the chemical bond, the concentration of H and D upload, and the stability of "graphane", also pointing at enlightening possible isotope dependences, of paramount importance in view of the perspective T application.