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The weak bonding of A atoms with MX layers in MAX phases not only enables the selective etching of A layers for MXene preparation but brings about the chance to construct A derivatives/MXene composites via in situ conversion. Here, a facile and general gas‐solid reaction systems are elegantly devised to construct multi‐dimensional MXene based composites including AlF3 nanorods/MXene, AlF3 nanocrystals/MXene, amorphous AlF3/MXene, A filled carbon nanotubes/MXene, layered metal chalcogenides/MXene, MOF/MXene, and so on. The intrinsic effect mechanism of interlayer confinement towards crystal growth, catalytic behavior, van der Waals‐heterostructure construction and coordination reaction are rationally put forward. The tight interface combination and synergistic effect from distinct components make them promising active materials for electrochemical applications. More particularly, the AlF3 nanorods/Nb2C MXene demonstrate bi‐directional catalytic activity toward the conversion between Li2S and lithium polysulfides, which alleviates the shuttle effect in lithium‐sulfur batteries. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The weak bonding of A atoms with MX layers in MAX phases not only enables the selective etching of A layers for MXene preparation but brings about the chance to construct A derivatives/MXene composites via in situ conversion. Here, a facile and general gas-solid reaction systems are elegantly devised to construct multi-dimensional MXene based composites including AlF 3 nanorods/MXene, AlF 3 nanocrystals/MXene, amorphous AlF 3 /MXene, A filled carbon nanotubes/MXene, layered metal chalcogenides/MXene, MOF/MXene, and so on. The intrinsic effect mechanism of interlayer confinement towards crystal growth, catalytic behavior, van der Waals-heterostructure construction and coordination reaction are rationally put forward. The tight interface combination and synergistic effect from distinct components make them promising active materials for electrochemical applications. More particularly, the AlF 3 nanorods/Nb 2 C MXene demonstrate bi-directional catalytic activity toward the conversion between Li 2 S and lithium polysulfides, which alleviates the shuttle effect in lithium-sulfur batteries., (© 2024 Wiley-VCH GmbH.)