High-Throughput Production of 1T MoS<sub>2</sub> Monolayers Based on Controllable Conversion of Mo-Based MXenes.

Du, Zhiguo; Guo, Yu; Wang, Haiyang; Gu, Jianan; Zhang, Yongzheng; Cheng, Zongju; Li, Bin; Li, Songmei et al. · ACS Nano · 2021

basic_science · Level V

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Abstract

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 (<i>e.g.</i>, exfoliation) and bottom-up (<i>e.g.</i>, chemical vapor deposition) approaches. Here, 1T MoS<sub>2</sub> monolayers with a very high fraction of ∼90% were achieved <i>via</i> the conversion of Mo-based MXenes (Mo<sub>2</sub>CT<sub><i>x</i></sub> and Mo<sub>1.33</sub>CT<sub><i>x</i></sub>) at high temperatures in hydrogen sulfide gas, in which the Mo-layer of Mo-based MXenes could be transformed to MoS<sub>2</sub> monolayers and the Mo vacancies facilitate the gliding of sulfur layers to form 1T MoS<sub>2</sub>. The resultant 1T MoS<sub>2</sub> monolayers with numerous vacancies exhibit strong chemisorption and high catalytic activity for lithium polysulfides (LiPSs), delivering a reversible capacity of 736 mAh g<sup>-1</sup> at 0.5 C, a superior rate capability of 532 mAh g<sup>-1</sup> at 5 C, and a good stability up to 200 cycles at 1 C in lithium-sulfur (Li-S) batteries.