2D Zn-Hexamine Coordination Frameworks and Their Derived N-Rich Porous Carbon Nanosheets for Ultrafast Sodium Storage

Metal-organic coordination frameworks have been widely used as efficient precursors for the preparation of functional carbon-based materials with various nanostructures. However, to date, the design of 2D carbon nanostructures from single coordination frameworks remains a great challenge. Herein, an efficient strategy for the fabrication of N-rich porous carbon nanosheets from 2D Zn-hexamine coordination framework nanosheets is developed. Remarkably, the N-doping level of carbon nanosheets can attain 16.54 at%. In addition, the thickness of the carbon nanosheets can effectively be tuned by simply adjusting the molar ratio of the starting materials. As a proof-of-concept application, the as-prepared carbon nanosheets as an anode material for sodium-ion batteries exhibit an ultrafast sodium storage capability of 194 mAh g(-1) even at 10 A g(-1). As far as it is known, such a high-rate capability has been rarely achieved in previous studies on carbonaceous anode materials for Na-ion storage. Moreover, this approach is readily controllable and could be extended to prepare a series of 2D N-doped carbon-based nanomaterials on a large scale.