High-Throughput Production of 1T MoS2 Monolayers Based on Controllable Conversion of Mo-Based MXenes.

Although transition metal dichalcogenides (TMDs) monolayers are widely applied in electronics, optics, catalysis, and energy storage, their yield or output is commonly very low (<1 wt % or micrometer level) based on the well-known top-down (e.g., exfoliation) and bottom-up (e.g., chemical vapor deposition) approaches. Here, 1T MoS2 monolayers with a very high fraction of ∼90% were achieved via the conversion of Mo-based MXenes (Mo2CTx and Mo1.33CTx) at high temperatures in hydrogen sulfide gas, in which the Mo-layer of Mo-based MXenes could be transformed to MoS2 monolayers and the Mo vacancies facilitate the gliding of sulfur layers to form 1T MoS2. The resultant 1T MoS2 monolayers with numerous vacancies exhibit strong chemisorption and high catalytic activity for lithium polysulfides (LiPSs), delivering a reversible capacity of 736 mAh g-1 at 0.5 C, a superior rate capability of 532 mAh g-1 at 5 C, and a good stability up to 200 cycles at 1 C in lithium-sulfur (Li-S) batteries.