General and Fast Gas-Solid Synthesis of Functional MXenes and Derivatives on the Scale of Tens of Grams.

The rising of MXenes not only enriches the two-dimensional material family but also brings more opportunities for diverse functional applications. However, the controllable synthesis of MXenes is still unsatisfied via the common liquid-solid etching route, considering the unsolved problems like safety risk, time cost and easy oxidation. Herein, a facile yet efficient gas-solid (G-S) reaction methodology is devised by using hydrogen fluoride gas derived from fluorinated organics as the MAX etchant toward high-efficiency fabrication of multiple MXenes and their derivatives. The innovative G-S reaction strategy exhibits superb versatility to achieve different gram-level MXenes (V2C, Ti3C2, Nb2C, Ti2N, Ti3CN, (Mo2/3Y1/3)2C) in a very short time, and even realizes in situ heteroatom doping or synchronous phase conversion of MXenes directly from MAX phases. The obtained MXenes and their derivatives exhibit excellent structure stability and high electron/ion conductivity, making them promising materials for electrochemical applications. In particular, the N-doped V2C MXene shows superior adsorption and catalytic activity toward lithium polysulfides for advanced lithium sulfur batteries.