Exfoliation of MoS₂ Nanosheets Enabled by a Redox-Potential-Matched Chemical Lithiation Reaction

Abstract

Ion intercalation assisted exfoliation is the oldest and most popular method for the scalable synthesis of molybdenum disulfide (MoS2) nanosheets. The commonly used organolithium reagents for Li+ intercalation are n-butyllithium (n-BuLi) and naphthalenide lithium (Nap-Li); however, the highly pyrophoric nature of n-BuLi and the overly reducing power of Nap-Li hinder their extensive application. Here, a novel organolithium reagent, pyrene lithium (Py-Li), which has intrinsic safe properties and a well-matched redox potential, is reported for the intercalation and exfoliation of MoS2. The redox potential of Py-Li (0.86 V vs Li+/Li) is located just between the intercalation (1.13 V) and decomposition (0.55 V) potentials of bulk MoS2, thus allowing precise Li+ intercalation to form a lamellar LiMoS2 compound without undesirable structural damage. The lithiation reaction can be accomplished within 1 h at room temperature and the exfoliated nanosheets are almost single layer. This method also offers the advantages of low cost, high repeatability, and ease in realizing large-scale production.

High-yield exfoliation of MoS2 nanosheets by a novel spray technique and the importance of soaking and surfactants

“…S1 (b)). As reported previously 33 , it corresponds to the (100) plane of MoS2, which is shown as the inset of Fig. 2 (b).…”

Layer-Structured Anisotropic Metal Chalcogenides: Recent Advances in Synthesis, Modulation, and Applications

“…Selection of intercalating molecules determines the interlayer space of the MCs nanocrystals. This section reviews exfoliation in liquid phase, including solvent-assisted exfoliation, − surfactant-assisted exfoliation, − chemical intercalation-induced exfoliation, − and electrochemical intercalation-induced exfoliation. − …”

A Review of Chemically Induced Intercalation and Deintercalation in Battery Materials

“…Intercalation of the zero‐valent copper metal was achieved by mixing Cu metal with Mo 6 S 8 and storing the pelletized powder at 80 C for 36 h. [ 69 ] For MoS 2 , the process of tuning interlayer spacing by intercalation can be further expanded to chemically exfoliate MoS 2 nanosheets. [ 70 ] Chemical lithium intercalation using n ‐butyllithium, followed by sonication, has also been successfully applied to produce GeP nanosheets for their application in sodium‐ion batteries. [ 71 ] Famously, the same mechanism is applied in many MXene exfoliation strategies.…”