Finite-size scaling effects of chemically induced transformations: From T12‑carbon to a composite carbon-cage structure

Abstract

In recent years, a single-layer two-dimensional (2-D) carbon material, penta-graphene, with an unusual negative Poisson's ratio and ultrahigh ideal strength has been gaining traction. Surprisingly, however, this excellent 2-D material is still in the conceptual stage, even the T12‑carbon for the synthesis of penta-graphene has not received proper attention. Herein, the finite-size scaling effects of the chemically induced transformation of the T12‑carbon structure with a stacking fault (AA-T12 carbon) is investigated using first-principles calculations. The results show that the AA-T12 carbon structure can very easily form a cage structure under the action of chemical induction, and the AA-T12 carbon-cage structure displayed satisfactory mechanical properties (Vickers hardness values of ≈62 GPa and a Young's modulus of 882 GPa). More importantly, the molecular dynamics simulation further indicates that this AA-T12 carbon cage@penta-graphene composite structure (which is named Y26, and composed with layered penta-graphene and AA-T12 carbon cage) can be used as excellent particle reinforcement material. This excellent result can be attributed to the AA-T12 carbon cage can provide high impact strength and high wear resistance, penta-graphene may provide the toughness and Poisson's ratio, and the gradient structure between the two phases may prevent the peeling of the hard phase. Therefore, we believe that Y26 provides a new path for penta-graphene and T12‑carbon applications.