Scalable, High-Yield Monolayer MXene Preparation from Multilayer MXene for Many Applications.

MXene (TiCT) is renowned for its exceptional conductivity and hydrophilicity; however, the low yield of monolayers hinders its industrial scalability. Herein, we present a strategy to substantially enhance the monolayer yield by disrupting the hydrogen-bonding cage confinement of multilayer MXene using high-temperature ultrasound, challenging the conventional belief that monolayer MXene can only be prepared at lower temperatures. At approximately 70 °C, the weakened hydrogen bonding between the oxygen-containing terminal groups of multilayer MXene and surrounding water molecules weakens the hydrogen-bond cage confinement. This enables ultrasonic cavitation to generate more microbubbles that penetrate the interlayers of multilayer MXene, resulting in gentle and thorough delamination into larger monolayer nanosheets. Achieving up to a 95 % yield in just tens of minutes, these nanosheets exhibit properties comparable to those produced by traditional ice-bath methods. Furthermore, the high-concentration MXene ink produced on a large scale using this high-yield approach exhibits excellent printing and processing capabilities, and the corresponding products showcase superior infrared stealth and Joule heating characteristics. This work addresses a key technical bottleneck in MXene production, paving the way for its extensive technological and industrial applications.