Neutron scattering of parent and reduced graphene oxides

The current paper summarizes results of an extended neutron scattering study of a three-part set of parent and reduced graphene oxide (GO and rGO, respectively) of different origin. The first part concerned the rGO of natural origin presented by wet and dry shungite carbons [1,2], the second was related to synthetic GO and rGO with the latter produced in the course of chemical treatment [3], the third part presents another pair of synthetic GO/rGO products with the latter produced via thermo exfoliation of the parent GO [4]. The study involved both the neutron diffraction (ND) and inelastic neutron scattering (INS). The neutron diffraction patterns confirmed stacking structures of all the species consisting of a number of layers of nanosize (natural products) and microsize (synthetic products) lateral dimension and the interlayer distances of 7.0-7.2 Å and 3.4-3.5 Å for GO and rGO, respectively. One-phonon amplitude-weighted density of vibrational states G(ω) represents the inelastic incoherent neutron scattering spectra of the products. The obtained data are analyzed basing on calculated G(ω) functions. The performed study has convincingly shown that neutron scattering clearly distinguishes GO and rGO species and well exhibits both common features and differences related to the members of the two communities. If retained water in GOs and graphene-hydride nature of rGOs provide the commonality of dynamic properties within each of the community, the difference in the relevant sheet topology is responsible for a noticeable variability of the latter. The study has convincingly shown a large polyvariance of both GO and rGO products evidencing their topochemical nature. © 2017 Advanced Study Center Co. Ltd.