Advanced Materials Laboratory, Sandia National Laboratories , Albuquerque, New Mexico 87185, United States.
J Am Chem Soc. 2015 Feb 11;137(5):1742-5. doi: 10.1021/ja5107145. Epub 2015 Feb 3.
Lithiation-exfoliation produces single to few-layered MoS2 and WS2 sheets dispersible in water. However, the process transforms them from the pristine semiconducting 2H phase to a distorted metallic phase. Recovery of the semiconducting properties typically involves heating of the chemically exfoliated sheets at elevated temperatures. Therefore, it has been largely limited to sheets deposited on solid substrates. Here, we report the dispersion of chemically exfoliated MoS2 sheets in high boiling point organic solvents enabled by surface functionalization and the controllable recovery of their semiconducting properties directly in solution. This process connects the scalability of chemical exfoliation with the simplicity of solution processing, ultimately enabling a facile method for tuning the metal to semiconductor transitions of MoS2 and WS2 within a liquid medium.
锂化-剥离产生可分散在水中的单层至少数层的 MoS2 和 WS2 片。然而，该过程会将它们从原始的半导体 2H 相转变为扭曲的金属相。半导体性能的恢复通常涉及将化学剥离的薄片在高温下加热。因此，它在很大程度上仅限于沉积在固体衬底上的薄片。在这里，我们报告了通过表面功能化在高沸点有机溶剂中分散化学剥离的 MoS2 薄片，并可直接在溶液中控制其半导体性能的恢复。该过程将化学剥离的可扩展性与溶液处理的简单性联系起来，最终在液体介质中为 MoS2 和 WS2 的金属到半导体转变提供了一种简便的方法。
