# Wrinkled Janus SMoSe–XS2 (X = Mo, W) heterostructures: coupling mechanical flexibility with enhanced HER

## TL;DR

This paper shows that Janus TMD heterostructures can be both mechanically flexible and highly efficient for hydrogen production.

## Contribution

The study introduces SMoSe–XS2 (X = Mo, W) Janus heterostructures with enhanced mechanical and catalytic properties due to their wrinkled interfaces.

## Key findings

- In-plane SMoSe–XS2 heterostructures form sinusoidal superlattices with over fivefold fracture strain enhancement.
- Wrinkled interfaces improve HER activity with Gibbs free energies as low as −0.18 eV due to p-band center shifts.
- Structure-mechanical response correlation is evident in Armchair and Zigzag configurations.

## Abstract

Janus transition-metal dichalcogenide (TMD) heterostructures offer unique opportunities for coupling mechanical flexibility with catalytic functionality. Molecular dynamics simulations reveal that in-plane SMoSe–XS2 (X = Mo, W) heterostructures spontaneously form sinusoidal superlattices driven by interfacial asymmetry, exhibiting over fivefold enhancement in fracture strain and pronounced size-dependent strength. The periodic profile of Armchair and Zigzag configurations highlights the intrinsic link between structure and mechanical response. Density functional theory calculations further demonstrate that the wrinkled interfaces significantly improve hydrogen evolution reaction (HER) activity, with Gibbs free energies as low as −0.18 eV, resulting from the upward shift of the Se and S p-band centers near the Fermi level, facilitating optimal H adsorption. This work establishes Janus TMD heterostructure superlattices as promising candidates for multifunctional applications integrating mechanical adaptability and catalytic efficiency.