High-Yield, Sustainable Production of High-Quality Ti ₃ C ₂ T _<i>x</i> MXene with Enhanced Oxidation Stability via Hydrothermal Etching and Water Delamination

Ti 3 C 2 T x MXene is studied for its high electrical conductivity and unique surface chemistry, enabling applications in energy storage, electronics, and electromagnetic interference (EMI) shielding. However, conventional synthesis based on hydrofluoric acid etching and intercalation-assisted delamination often leads to low yield, structural degradation, and environmental concerns, limiting the scalability. Here, we report a hydrothermal etching method followed by water-only delamination to produce high-quality MXene. The hydrothermal process yields 98% multilayer Ti 3 C 2 T x, and subsequent delamination proceeds through water intercalation without lithium ions or organic intercalants, simplifying the process. The resulting few-layer MXene exhibits an average thickness of 1.8 nm, a lateral size of 3.7 μm, and an electrical conductivity of 15,230 S cm –1, along with enhanced oxidation stability under ambient conditions. An ultrathin freestanding Ti 3 C 2 T x film (430 nm) achieves a specific shielding effectiveness per thickness of 4.81 × 10 5, demonstrating its potential for scalable and sustainable EMI shielding applications.