Small transition-metal dichalcogenide nanostructures down to subnanometer by two-dimensional material origami

Abstract

Origami is a promising method for creating various structures from filmlike materials via local deconstruction rather than elastic bending. Transition-metal dichalcogenides (TMDCs) have high bending stiffness making the formation of highly curved nanostructures, such as nanotube or nanocages, via bending difficult. Here, we propose the use of two-dimensional (2D) material origami to build stable TMDC nanostructures. Various nanostructures, such as polygonal nanotubes or polyhedral nanocages, can be created by introducing line defects, which incurs only a very small energy penalty. Through first-principles calculations and high-resolution transmission electron microscopy imaging, we confirmed their stability and the possibility of synthesis experimentally via line defect formation. As an example, the widely observed TMDC nanowires are produced with this approach, and many experimentally observed nanostructures agree with these origami creases/line defects. This work opens a door to synthesize nanostructures of few-atomic-thick 2D materials for various potential applications.