Two-Dimensional NiSe2/N-Rich Carbon Nanocomposites Derived from Ni-Hexamine Frameworks for Superb Na-Ion Storage.

Design of functional carbon-based nanomaterials from metal-organic frameworks (MOFs) has attracted soaring interests in recent years. However, a MOF-derived strategy toward two-dimensional (2D) nanomaterials remains a great challenge. In this work, we develop a layered Ni-hexamine framework as efficient precursor to prepare a 2D NiSe2/N-rich carbon nanocomposite by a simple pyrolysis and subsequent selenization process. In the 2D NiSe2/N-rich carbon nanocomposite, NiSe2 nanoparticles with diameters of ca. 75 nm are homogeneously distributed in the N-rich carbon nanosheets. When serving as anode materials for sodium-ion batteries, the 2D nanocomposites exhibit a high reversible capacity of 410 mAh g-1 at 1 A g-1 and maintain a value of 255 mAh g-1 even at 10 A g-1. The excellent electrochemical performance can be attributed to the synergistic effects between the N-rich carbon nanosheets and NiSe2 nanoparticles. More importantly, the hexamine-based MOFs can be regarded as new and powerful platforms for the fabrication of 2D N-rich carbon-based nanomaterials, which is of great importance for various potential applications.