The exfoliation of bulk 2H-molybdenum disulfide (2H-MoS₂) into few-layer nanosheets with 1T-phase and controlled layers represents a daunting challenge towards the device applications of MoS₂. Conventional ion intercalation assisted exfoliation needs the use of hazardous n-butyllithium and/or elaborate control of the intercalation potential to avoid the decomposition of the MoS₂. This work reports a facile strategy by intercalating Li ions electrochemically with ether-based electrolyte into the van der Waals (vdW) channels of MoS₂, which successfully avoids the decomposition of MoS₂ at low potentials. The co-intercalation of Li⁺ and the ether solvent into MoS₂ makes a first-order phase transformation, forming a superlattice phase, which preserves the layered structure and hence enables the exfoliation of bulk 2H-MoS₂ into bilayer nanosheets with 1T-phase. Compared with the pristine 2H-MoS₂, the bilayer 1T-MoS₂ nanosheets exhibit better electrocatalytic performance for the hydrogen evolution reaction (HER). This facile method should be easily extended to the exfoliation of various transition metal dichalcogenides (TMDs).

将块状 2H-二硫化钼 (2H-MoS ₂ ) 剥离成具有 1T 相和受控层的少层纳米片对 MoS ₂的器件应用提出了严峻的挑战。传统的离子嵌入辅助剥离需要使用危险的正丁基锂和/或精心控制嵌入电势以避免MoS ₂的分解。_{这项工作报告了一种简单的策略，通过将锂离子与基于醚的电解质电化学插入MoS 2}的范德华（vdW）通道中，成功地避免了MoS ₂在低电势下的分解。^{Li +}和醚溶剂共嵌入MoS ₂中，发生一级相变，形成超晶格相，从而保留了层状结构，从而使块体2H-MoS ₂剥离成具有1T相的双层纳米片。与原始的2H-MoS ₂相比，双层1T-MoS ₂纳米片对析氢反应（HER）表现出更好的电催化性能。这种简便的方法应该很容易扩展到各种过渡金属二硫属化物（TMD）的剥离。