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

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 <i>p</i>-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.