Ab initio investigation of the interface between [formula omitted] nanoflakes and the [formula omitted] surface: Interplay between interaction energy and morphology

Abstract

MoS2 nanoflakes have attracted wide attention due to their outstanding catalytic activity induced by their active zigzag edges. Nanoflakes morphologies dictate their electronic properties, and factors such as size, doping, and interaction with a substrate determines their behavior. Herein, we investigate the role of the Au(111) substrate in the morphology of Mo10S24 nanoflakes via first-principles density functional theory calculations combined with the k-means clustering algorithm for structure selection. From our initial calculations for gas-phase nanoflakes, we found that asymmetric morphologies are about 2.7eV lower in energy than the symmetric ones. Thus, we deposited a few nanoflakes on the Au(111) substrate to investigate their effects. Here, we obtain a strong nanoflake/gold interaction ruled by features such as symmetry, roughness, and vertical S–Au stacking. The S–Au interaction is large enough to change the relative energies between the nanoflakes in the gas-phase by more than 2.0eV, which indicates the relevance of substrate engineering for the nanoflake morphology.