Growth of self-aligned nonlayered TaC nanosheets on liquid copper by a solid phase diffusion strategy

Compared with layered 2D materials, nonlayered 2D materials combine atomic thickness and high-activity surface, leading to many unique properties. Herein, a solid phase diffusion strategy is raised to obtain self-aligned nonlayered TaC single crystals on liquid copper. Because of the immiscibility of Cu and Ta, a β-Ta nanolayer with a thickness of ∼7 nm would form on the surface of liquid copper by a long-time solid phase diffusion process. After introducing CH4, the β-Ta nanolayer could be converted into 10 μm TaC single crystals with a thickness of 10 nm. With the extension of the reaction time, TaC single crystals would form an ordered self-aligned state spontaneously under the action of lateral capillary force. Finally, the self-aligned TaC nanosheets are assembled into large-size TaC films with a thickness of 10 nm. This strategy paves a new way to grow large-size nonlayered 2D transition metal carbides.