In Situ Solid Lithiation for Massive Exfoliation of 2D Metal Tellurides

Two-dimensional transition metal tellurides (2D TMTs) have emerged as promising candidates for optoelectronics and energy applications owing to their distinctive physicochemical properties. Nevertheless, the massive production of high-quality 2D TMTs remains a formidable challenge when using conventional exfoliation methods. Herein, we present an efficient, safety-compliant in situ solid lithiation exfoliation strategy utilizing lithium iodide (LiI) as a photothermally active intercalant for the mass production of high-quality TMT nanosheets (PdTe₂, MoTe₂, WTe₂, NbTe₂) with large lateral size (∼10 μm) and ultrathin thicknesses (2-4 nm). The process leverages synergetic ultraviolet (UV) irradiation and thermal activation to drive the decomposition of LiI, releasing iodine vapor and enabling efficient lithium intercalation without generating explosive byproducts. Remarkably, this method can produce 201.9 g of NbTe₂ nanosheets in a single batch, achieving an average yield of ∼85.7%. The universality of this protocol is demonstrated through the successful exfoliation of various alloyed tellurides (PdSeTe, NbSeTe, Pd_0.5Nb_0.5Te₂, and Pd_0.5Mo_0.5Te₂) and conventional 2D materials (BN, MoS₂). Furthermore, the high electrical conductivity and solution processability of the exfoliated 2D TMTs enable the formulation of functional inks for printed electronics and high-sensitivity piezoresistive sensors. This work establishes a scalable, safe, and efficient platform for the manufacturing of 2D TMTs, effectively overcoming the long-standing scalability bottleneck in nanomaterial synthesis.