Exploring the electron density localization in MoS2 nanoparticles using a localized-electron detector: Unraveling the origin of the one-dimensional metallic sites on MoS2 catalystsElectronic supplementary information (ESI) available: Fig. S1. Pictures showing that most of the delocalized electrons (LED < 0.3 a.u.) are inside the basins of the Mo atoms at the n8-100S cluster central layer. 2. Electron localized-electron detector analysis for the n6-50S cluster supported on an Au(111) layer. See D

• Main Authors: Aray, Yosslen, Barrios, Antonio Díaz
• Format: Article
• Language: English
• ISSN: 1463-9076; 1463-9084
• DOI: 10.1039/c8cp03387k

The nature of the electron density localization in two MoS 2 nanoclusters containing eight rows of Mo atoms, one with 100% sulphur coverage at the Mo edges ( n 8_100S) and the other with 50% coverage ( n 8_50S) was studied using a localized-electron detector function defined in the local moment representation. For n 8_100S, pairs of neighboring S 2 dimers cover the edges and the electron density localization function analysis shows the presence of a local triangular-shaped ring zone of highly delocalized electrons along these edges, which corresponds to a good metallic conductor zone. The optimized geometry analysis shows that the Mo-S 2 bond length is much longer than that of the Mo-S bonds inside the cluster. The removal of one S atom from each sulphur dimer to create a cluster with 50% coverage produces a general compressive stress on the cluster optimized geometry, which shortens the Mo-S bond length, particularly at the edge. The electron density location function analysis shows that close to the cluster corners, a zone of highly delocalized electron zones with a characteristic semiconductor pattern and broken one-dimensional metallic ring was generated. These results suggest that the Mo-S 2 bond elongation produced by the sulphur dimers is similar to a MoS 2 monolayer under tensile strain and is the origin of the one-dimensional metallic sites at the Mo-edges. In general, the present findings show excellent agreement with the key features of the reported ambient pressure X-ray photoemission spectra and the corresponding simulated scanning tunneling microscopy images. The nature of the electron density localization in two MoS 2 nanoclusters containing eight rows of Mo atoms, one with 100% sulphur coverage at the Mo edges ( n 8_100S) and the other with 50% coverage ( n 8_50S) was studied using a localized-electron detector function defined in the local moment representation.