Hydrogenation and defect formation control the strength and ductility of MoS2 nanosheets: Reactive molecular dynamics simulation

TL;DR

This study uses reactive molecular dynamics simulations to examine how hydrogenation and defects influence the mechanical strength and ductility of MoS2 nanosheets, providing insights for nanodevice design.

Contribution

It is the first detailed simulation study analyzing the combined effects of hydrogen functionalization and defects on MoS2's mechanical properties.

Findings

Hydrogenation and defects reduce elastic modulus and tensile strength.

Increased defects lead to lower stretchability and earlier failure.

Mechanical properties can be tuned via defect and hydrogen content.

Abstract

Two-dimensional (2D) molybdenum disulfide (MoS2) has attracted significant attention because of its outstanding properties, suitable for application in several critical technologies like, solar cells, photocatalysis, lithium-ion batteries, nanoelectronics, and electrocatalysis. Similar to graphene and other 2D materials, the physical and chemical properties of MoS2 can be tuned by the chemical functionalization and defects. In this investigation, our objective is to explore the mechanical properties of single-layer MoS2 functionalized by the hydrogen atoms. We moreover analyze the effects of different types of defects on the mechanical response of MoS2 at the room temperature. To investigate these systems, we conducted reactive molecular dynamics simulations using the ReaxFF forcefield. We demonstrate that an increase in the hydrogen adatoms or defects contents significantly affects the critical mechanical characteristics of MoS2, elastic modulus, tensile strength, stretchability and failure behavior. Our reactive molecular dynamics results provide useful information concerning the mechanical response of hydrogenated and defective MoS2 and the design of nanodevices.