High-Throughput Production of 1T MoS 2 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 MoS 2 monolayers with a very high fraction of ∼90% were achieved via the conversion of Mo-based MXenes (Mo 2 CT x and Mo 1.33 CT x ) at high temperatures in hydrogen sulfide gas, in which the Mo-layer of Mo-based MXenes could be transformed to MoS 2 monolayers and the Mo vacancies facilitate the gliding of sulfur layers to form 1T MoS 2 . The resultant 1T MoS 2 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.