Molecular dynamics study on the mechanical behavior of vertically aligned γ-graphdiyne-graphene heterostructures under tension

Abstract

Carbon-based two-dimensional (2D) materials and their applications have attracted extensive attention. Among them, vertically aligned gamma-graphdiyne/graphene (gamma-GDY/graphene) van der Waals heterostructures have been extensively studied by researchers due to their inherent advantages such as unique structures with uniformly distributed pores, high conductivity and easy accessibility. We construct a model for gamma-GDY/graphene heterostructures. The objective of this study is to promote the design of gamma-GDY/graphene heterostructures with improved mechanical properties and reveal the underlying microscopic mechanisms behind their enhanced mechanical performance. The molecular dynamics (MD) method is primarily employed in this study to explore the influence and mechanisms of external factors, such as temperature and loading direction, on their mechanical properties. It is found that with the increase of temperature, the Young's modulus and ultimate stress of gamma-GDY/ graphene heterostructures exhibit a decreasing trend. Under uniaxial tension, the ultimate stress predominantly relies on the alignment between the direction of chemical bonds and the stretching direction. This paper significantly impacts the design and application of carbon-based heterostructure materials.