Powder vaporization is a commonly used laboratory method for growing high-quality two-dimensional molybdenum disulfide crystals because it is simple and cost-effective. The gas-phase sulfurization of molybdenum trioxide by elemental sulfur is important and poorly understood. In our recent study (J. Phys. Chem. A. 2018, 122, 7320-7327), ab initio calculations of the thermodynamics of the reaction between molybdenum trioxide and sulfur allotropes showed that sulfurization occurs by three addition-elimination steps, each involving the formation of molybdenum oxysulfide rings and the dissociation of the rings into a more sulfurized molybdenum compound and sulfur oxides. Here, we use molecular dynamics simulations and ab initio calculations to shed light on the kinetics of the first step of the sulfurization process. Molecular dynamics simulations reveal the unique role disulfur and trisulfur play in the chemistry of sulfurization and ab initio calculations unfold the reaction paths necessary for the complete sulfurization to occur. Taken together, our analyses show that the optimal temperature range for the sulfurization process is between 1000 K and 1100 K, which is in agreement with the typical experimental growth temperatures.

Uncovering the kinetics of sulfurization of molybdenum trioxide by elemental sulfur in the growth of two-dimensional molybdenum disulfide by powder vaporization

2019 Fall National Meeting

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