▎ 摘　　要

A theoretical study on the geometric and electronic structure of C-60 and Sc3N@C-80 absorbed on pristine graphene nanoflakes (GNFs) is presented. C-60 is found to adsorb in two nearly degenerate configurations: with a pentagon facing the GNF, which is the most stable one, and with a hexagon facing the GNF in a face-to-face perfect alignment, rarely common in pi-pi interactions, 0.06 eV higher in energy. The calculated binding energy of 0.76 eV, which includes dispersion effects, is in good agreement with previous theoretical and experimental reports. On the contrary, Sc3N@C-80 adsorption on the GNF resulted in a higher binding energy of 1.00 eV for nearly degenerate isomers that have a pentagon and a hexagon facing the SLG. This larger binding energy is explained in terms of a higher dispersion interaction between the larger metallofullerene and the GNF, and due to the fact that charge separation in Sc3N@C-80, which results in a positively charged Sc3N inside a negatively charged C-80, favors binding with the GNF. Furthermore, the Sc3N moiety is found to rotate inside the supported C-80 fullerene, which in combination with the orientation of the fullerene on the SLG leads to a series of isomers with binding energies ranging from 0.76 to 1.00 eV. Our results show that it could be possible to adsorb metallofulleres on graphene nanoflakes with an energy large enough to prevent diffusion, therefore opening the possibility to potential applications.