Solvation Structure Regulated Intercalation Chemistry Enables Scalable and Oxidation-Suppressed Monolayer MXenes

The scalable production of high-quality monolayer MXenes is essential but remains challenging due to a persistent yield-quality dilemma during ion intercalation. Conventional hydrated lithium ions ([Li⁺(H₂O)_x]) provide insufficient steric expansion to overcome interlayer interactions, resulting in limited monolayer yields, while the water molecules inevitably induce surface oxidation and compromise material quality. Herein, we report a universal Li⁺ solvation structure regulation strategy to address this limitation. By leveraging the strong coordination of dimethyl sulfoxide (DMSO) to displace water, the enlarged and water-deficient ([Li⁺(DMSO)_x(H₂O)_y]) supramolecular clusters are constructed. The tailored solvation structure simultaneously expands interlayer spacing and forms a hydrophobic interfacial barrier via electron-transfer-induced DMSO chemisorption, enabling a high monolayer yield of 95.4% while effectively suppressing oxidation. Importantly, this scalable protocol (100 g scale) exhibits broad applicability to challenging MAX precursors (e.g., Ti₃AlCN and Ti₂AlC), enabling the mass production of diverse oxidation-resistant MXenes. The resulting films show excellent environmental stability and reliable performance in electromagnetic-interference shielding and infrared thermal camouflage.