Towards a better understanding of the structure of diamanoïds and diamanoïd/graphene hybrids

We report new evidences confirming the sp2–C to sp3–C conversion from electron diffraction at low energy, Raman spectroscopy and Density Functional Theory (DFT) calculations. Partial sp2–C to sp3–C conversion generates couples of twisted, superimposed coherent domains (TCD), supposedly because of stress relaxation, which are evidenced by electron diffraction and Raman spectroscopy. TCDs come with the occurrence of a twisted bilayer graphene feature located at the interface between the upper diamanoïd domain and the non-converted graphenic domain underneath, as evidenced by a specific Raman signature consistent with the literature. DFT calculations show that Raman T peak originates from a combination of the sp3–C stretching mode of a sp3–C layer with the optical out-of-plane mode of a graphene layer; both layers being sandwiched between a highly hydrogenated sp3–C surface and the underneath unconverted graphene layer(s).Graphical abstract
Source: Carbon - Category: Materials Science Source Type: research