Self-assembled Behaviors of Desulphurized $MoS_2$ Monolayer Sheets

TL;DR

This study uses molecular dynamics simulations to explore how desulphurization influences the self-assembled topological structures of MoS2 monolayer sheets, revealing diverse morphologies and the formation of nanotubes at critical defect levels.

Contribution

It demonstrates the impact of desulphurization on the morphology of MoS2 monolayers and highlights the role of defect engineering in tailoring 2D material properties.

Findings

Diverse topological structures depend on desulphurization levels.

Nanotube morphology appears at critical desulphurization content.

Differences in morphology are due to interatomic and van der Waals interactions.

Abstract

Self-assembled topological structures of post-processed two-dimensional materials exhibit novel physical properties distinct from those of their parent materials. Herein, the critical role of desulphurization on self-assembled topological morphologies of molybdenum disulfide ($MoS_2$) monolayer sheets is explored using molecular dynamics (MD) simulations. MD results show that there are differences in atomic energetics of $MoS_2$ monolayer sheets with different desulphurization contents. Both free-standing and substrate-hosted $MoS_2$ monolayer sheets show diversity in topological structures such as flat surface, wrinkles, folds and scrolls, depending on the desulphurization contents, planar dimensions and ratios of length-to-width of $MoS_2$ monolayer sheets. Particularly, at the critical desulphurization contents, they roll up into nanotube morphology, consistent with previous experimental observations. Moreover, the observed differences in the molecular morphological diagrams between free-standing and substrate-hosted $MoS_2$ monolayer sheets can be attributed to unique interatomic interactions and van der Waals interactions in them. The study provides important insights into functionalizing structural morphological properties of two-dimensional materials, e.g., $MoS_2$, via defect engineering.