AVS 60th International Symposium and Exhibition
    Surface Science Wednesday Sessions
       Session SS+NS-WeM

Paper SS+NS-WeM5
Characteristics of Sulfur-Vacancy Clusters in Single Layer MoS2: Insights from ab initio Calculations

Wednesday, October 30, 2013, 9:20 am, Room 201 A

Session: Nanostructures: Reactivity & Catalysis
Presenter: D. Le, University of Central Florida
Authors: D. Le, University of Central Florida
T.B. Rawal, University of Central Florida
T.S. Rahman, University of Central Florida
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Single-layer MoS2 is proving itself to be a versatile material for a wide variety of electronic, optical and chemical applications. Sulfur depletion, without destabilization of the single-layer, is considered a prudent way for making the basal plane of the layer catalytically active. We will present results of our density-functional-theory based examination of vacancy structures on one side of a MoS2 layer which point to their structural stability and chemical reactivity. We will show that the formation energy per sulfur vacancy is lowest (energetically favorable) when the vacancies form a row, and that the longer the row, the lower the formation energy. In addition, we will show that the lowest energetic barrier for spoiling these row structures by exchanging a vacancy with a nearby sulfur atom is 0.79 eV, and that this barrier increases as the row elongates. Furthermore, the presence of vacancy clusters will be shown to make the system thermodynamically facile for alcohol synthesis from syngas. (Work supported in part by DOE grant DE-FG02-07ER15842.)