Fig. 3
Theoretical calculations of oleamide assembly on monolayer MoS2. a 2D potential energy surface (PES) of a single oleamide molecule adsorbed on MoS2, with one oleamide subchain aligned along the zigzag lattice direction of substrate. The 2D PES exhibits the same hexagonal symmetry as the underlying lattice of MoS2. The energy valleys in blue represent the most stable adsorption positions for zigzag aligned oleamide molecules. b 1D projection along the x (zigzag) and y (armchair) directions of the same 2D PES in a. c Assembly of oleamide molecules on MoS2. Each oleamide molecule is adsorbed onto the MoS2 surface at the thermodynamically most stable position, as indicated by the energy valley of the 2D PES in a. The red arrow on the left indicates the orientation of the nanoribbon, which is exactly the zigzag lattice direction of MoS2. The color code of the atoms is Mo: light blue, S: yellow, C: gray, H: white, O: red, and N: dark blue, respectively
