New insight into bonding energy and stress distribution of graphene oxide/hexagonal boron nitride: Functional group and grain boundary effect

The stress accumulation and nonlinear buckling induced by grain boundaries (GBs) in two-dimensional (2D) interface and functional groups (FGs) on the surface of 2D are different from those of three-dimensional (3D) blocks. Topological and geometrical effects of defects and FGs in 2D materials will significantly affect their mechanical properties and transport behavior. A new graphene oxide/h-BN interface with GBs model (GO-BN-GBs) was constructed to study the built-in distortion stress and out-of-plane deformation caused by GBs and FGs under different strains. Considering GBs type, FGs type, FGs density and also the effect of distance between FGs and GBs on the bonding energy and stress distribution of GO-BN-GBs interface were studied by molecular dynamics (MD). The results show that the GBs and FGs exert a remarkable reduction in failure stress and strain as well as Von-mises stress, thereby decreasing the stability capacity and interfacial mechanical properties of GS under axial tension. However, the presence of GBs and FGs can slight improve the bending rigidities of 2D materials due to their interactions induced out-plane deformation. In addition, the geometrical effects and builtin distorted stress very sensitive to FGs types, FGs density and distance between GBs and FGs. The distortion stress and geometrical deformation caused by GBs and FGs will enrich the growth morphology of 2D materials, and will also lead to more interesting scientific problems, which is expected to become a new growth point of 2D materials research in the future.