Origin of the Phase Transition in Lithiated Molybdenum Disulfide

Abstract

Phase transitions and phase engineering in two-dimensional MoS2 are important for applications in electronics and energy storage. By in situ transmission electron microscopy, we find that H-MoS2 transforms to T-LiMoS2 at the early stages of lithiation followed by the formation of Mo and Li2S phases. The transition from H-MoS2 to T-LiMoS2 is explained in terms of electron doping and electron-phonon coupling at the conduction band minima. Both are essential for the development of two-dimensional semiconductor-metal contacts based on MoS2 and the usage of MoS2 as anode material in Li ion batteries.

Fast and Efficient Preparation of Exfoliated 2H MoS2 Nanosheets by Sonication-Assisted Lithium Intercalation and Infrared Laser-Induced 1T to 2H Phase Reversion

“…45,46 Despite its efficiency in producing monolayer MoS 2 , the chemical intercalation/exfoliation route always results in the loss of the semiconducting properties of pristine MoS 2 , because of the 2H to 1T phase change during Li intercalation. 42 In order to reverse this transformation, exfoliated MoS 2 sheets are typically annealed or heated in high boiling organic solvents at temperatures of 100−300°C under an inert atmosphere. 37,47 Considering the metastable nature of the metallic 1T phase of MoS 2 and the intrinsic strong infrared (IR) absorption of metallic materials (such as the 1T MoS 2 ), we hypothesized that the 1T phase could be thermally converted back to the 2H phase when exposed to IR radiation.…”

Origin of Structural Transformation in Mono- and Bi-Layered Molybdenum Disulfide

“…1, the layers are composed by prismatic D 3h -, octahedral O h -, and octahedral O h -disordered MoS 2 units, which are termed as 2H-, 1T- and 1T’-MoS 2 , respectively13. The electronic properties of the TMDs show a significant dependence on the polytypic structures13, for example, the 2H-MoS 2 phase shows a semiconductor nature, whereas the 1T-MoS 2 phases show a metallic character61415. The electronic properties of the TMDs can be tuned by applying strain16 or formation of heterostructures1718.…”

Structural‐Phase Catalytic Redox Reactions in Energy and Environmental Applications

“…In parallel, Enyashin and co‐workers have fabricated the 1T‐MoS 2 phase within WS 2 nanotubes along with rhenium (Re) doping, leading to stabilization of the 1T phase more profoundly than that of alkali intercalation into the lattice of the compound. Indeed, alkali intercalation has deleterious effects on phase transition since the transferred electrons from alkali metals could possibly enhance the electron density of the transition metal d‐orbital, leading to destabilization of the 2H phase and its conversion to either the metallic 1T or distorted 1T′ phase …”