▎ 摘　　要

The distinct effectiveness of graphene-based nanostructures, including pristine graphene, graphene with Stone Wales defects, graphene oxides, and multilayered graphene materials, toward the development of mechanically robust graphene polypyrrole nanocomposites are explored within the framework of density functional theory (DFT) computations employing long-range corrected hybrid M06-2X functional. The essence of interface interactions is derived from the finite models of graphene polymer systems by computing thermochemical properties, IR stretching frequencies, Raman scattering activities, global chemical reactivity descriptors, electronic properties via molecular orbital analysis, as well as charge density distribution of each of the nanocomposites. The binding affinity is also evaluated by executing DFT-D3 and MP2-based computations to account for interaction energies with a reasonable accuracy. The adsorption energy due to the attachment of polypyrrole entity on the pristine graphene surface is estimated to be about 25 kcal/mol at the M06-2X-D3 level, which is further enhanced to 28 and 34 kcal/mol, respectively, with the introduction of Stone Wales defect and epoxy groups on the graphene surface. The subtle interplay of noncovalent interactions has been ascertained from the electrostatic potential maps, the Becke isosurface maps, and the reduced density gradient isosurfaces of the hybrid complexes. The weak attractive interactions within the local areas between the pyrrole units and modified graphene surface involving pi-pi stacking, lone pair-pi, and H-bond interactions together accommodate the auxiliary binding strength of the hybrid complexes. The present findings bestow the formation mechanism and stabilizing factors in the integral structure of graphene polymer nanocomposites.