Bubbling Chemical\nVapors in Molten Metal toward XIV-Group\nNanosheets

Two-dimensional (2D) XIV-group nanosheets (germanene,\nsilicene,\nand stannene) possess unique physical and chemical features promising\nin fields of electronics, energy storage, and conversions. However,\npreparing these nanosheets is challenging owing to their non van der\nWaals structure with strong chemical bonds inside. Herein, a bubbling\nchemical-vapor growth method is proposed to synthesize these XIV-group\nnanosheets by bubbling XIV-group-element chlorides in molten sodium.\nDuring the synthetic process, XIV-group materials are formed by the\nreaction of XIV-group element chlorides with strong reducing sodium,\nthen nucleated, and finally isolated to 2D nanosheets in the gas–liquid\ninterface. With the collapse of vapor bubbles and subsequent injection,\n2D nanosheets are continuously produced. The nanosheets (Ge) possess\na thickness of ∼3.8 nm and a lateral size of ∼2.0 μm.\nCombining with graphene, the hybrid and flexible films are obtained,\ndelivering a volumetric specific capacity of 4785 mAh cm<sup>–3</sup> and superior cycling stability (over 4000 cycles) in lithium-ion\nbatteries