The Role of Molybdenum Oxysulfide Rings in the Formation of Two-Dimensional Molybdenum Disulfide by Powder Vaporization

Autor: Joshua A Maurer, Stephen F. Bartolucci, Thierry Tsafack
Rok vydání: 2018
Předmět:
Zdroj: The Journal of Physical Chemistry A. 122:7320-7327
ISSN: 1520-5215
1089-5639
DOI: 10.1021/acs.jpca.8b04891
Popis: Sulfurization of molybdenum trioxide by elemental sulfur through powder vaporization is a common method used for growth of molybdenum disulfide. Optimization of complexes between sulfur allotropes and molybdenum species using Density Functional Theory has revealed the molecular mechanism of sulfurization. Complete sulfurization of molybdenum trioxide to molybdenum disulfide requires at least three sets of nucleophilic addition-elimination reactions that generate the experimentally observed molybdenum oxysulfide intermediates along the reaction pathway. Each nucleophilic addition reaction of a sulfur allotrope to a molybdenum species gives rise to a molybdenum oxysulfide ring, which can dissociate into a more sulfurized molybdenum intermediate. At the typical growth temperatures used in powder vaporization, the equilibrium constants for these reactions are essentially unity. Thus, sulfurization is driven by excess sulfur and gas flow through the growth furnace.
Databáze: OpenAIRE