Defect Design of Two-Dimensional MoS₂ Structures by Using a Graphene Layer and Potato Stamp Concept

We propose a novel method to create vacancy defects on MoS₂ structures. The method is similar to a potato stamp process, which involves creating vacancy defects on a graphene layer and stamping to the MoS₂ surface. On the basis of nudged elastic band and density functional theory calculations, we predict that sulfur atoms on the surface will diffuse into the vacancy sites of the graphene layer. Separation of the graphene layer will carry away diffused sulfur atoms, leaving the MoS₂ surface with sulfur vacancy defects. We carried out molecular dynamics simulations with the ReaxFF reactive force field to test the potato stamp concept and then functionalized the MoS₂ surface defects with epoxy molecules. We observed dissociation of epoxy molecules at the vacancy site, in which the exposed metal atoms had catalytic activity.