A convenient ultrasonic path for van der Waals heterostructure construction: Study on MoS₂/graphene as an example

Ultrasound is a powerful tool in materials processing, yet its application in constructing van der Waals (vdW) heterostructures remains under-explored. In this study, MoS₂ and graphene — two widely studied 2D materials — were successfully assembled into vdW heterostructures via a convenient ultrasound-driven self-assembly approach. The morphology of the heterostructures was characterized by scanning electron microscopy (SEM), while their structural and compositional features were confirmed through x-ray diffraction (XRD), Raman spectroscopy, and x-ray photoelectron spectroscopy (XPS). Red-shifted Raman peaks and decreased binding energies in XPS spectra provided strong evidence of successful heterostructure formation. A three-stage assembly mechanism — comprising dispersion, assembly, and adjustment — is proposed, with acoustic cavitation playing a key role in driving the process. This study not only demonstrates the feasibility of synthesizing 2D heterostructures via an ultrasonic route but also lays a foundation for future scalable, energy-efficient fabrication strategies.