Ab initio insights into the stabilization and binding mechanisms of MoS2 nanoflakes supported on graphene

Author(s)

Caturello, Naidel A. M. S. ^[1] ; Silveira, V, Julian F. R. ; Da Silva, Juarez L. F. ^[2]

Affiliation

^[1] Univ Sao Paulo, Sao Carlos Inst Chem, POB 780, BR-13560970 Sao Carlos, SP - Brazil

^[2] Silveira, Julian F. R., V, Univ Sao Paulo, Sao Carlos Inst Chem, POB 780, BR-13560970 Sao Carlos, SP - Brazil

• Document type: Journal article
• Source: Physical Chemistry Chemical Physics; v. 22, n. 46, p. 26865-26875, DEC 14 2020.
• Web of Science Citations: 0

Abstract

An atomistic understanding of transition-metal dichalcogenide (TMD) nanoflakes supported on graphene (Gr) plays an important role in the tuning of the physicochemical properties of two-dimensional (2D) materials; however, our current atom-level understanding of 2D-TMD nanoflakes on Gr is far from satisfactory. Thus, we report a density functional theory investigation into the stabilization and binding mechanisms of (MoS2)(n)/Gr, where n = 1, 4, 6, 9, 12 and 16. We found an evolution of the (MoS2)(n) horizontal ellipsis Gr interactions from covalent and hybridization contributions for smaller nanoflakes (n = 1, 4) to vdW interactions for larger (MoS2)(n) nanoflakes (n >= 6); however, the coupling of the (MoS2)(n) and Gr electronic states for n = 1 and 4 is not intense enough to change the Dirac cones at the Gr monolayer. On average, the 1T `- and 2H-(MoS2)(n) nanoflakes bind with similar adsorption/interaction energies with Gr, and hence the (MoS2)(n) horizontal ellipsis Gr interactions do not change the high energetic preference of the 1T `- structures, which can be explained by the stabilizing role of the S-terminated edges in the 1T `-(MoS2)(n) in contrast with the destabilizing role of the edges in the 2H-(MoS2)(n) nanoflakes. (AU)

• FAPESP's process: 18/21401-7 - Multi-User Equipment approved in grant 2017/11631-2: cluster computational de alto desempenho - ENIAC
• Grantee: Juarez Lopes Ferreira da Silva
• Support Opportunities: Multi-user Equipment Program
• FAPESP's process: 17/11631-2 - CINE: computational materials design based on atomistic simulations, meso-scale, multi-physics, and artificial intelligence for energy applications
• Grantee: Juarez Lopes Ferreira da Silva
• Support Opportunities: Research Grants - Research Centers in Engineering Program