Two-dimensional Cr2O3 and interconnected graphene–Cr2O3 nanosheets: synthesis and their application in lithium storage

Abstract

In this manuscript, we have proposed a new facile method for the synthesis of pure Cr₂O₃ nanosheets without foreign templates for the first time. We used Na₂CrO₄ and graphene oxide as the oxidant and reductant templates, respectively, in a hydrothermal reaction in order to synthesize porous Cr(OH)₃ nanosheet precursors. By controlling the proportion of graphene oxide and Cr(VI), the carbon framework could be partially retained, resulting in graphene-divided porous Cr(OH)₃ nanosheets. After calcination at 700 °C, these graphene oxide-derived Cr(OH)₃ nanosheets were transformed into pure Cr₂O₃ nanosheets or interconnected graphene–Cr₂O₃ nanomaterials. The graphene–Cr₂O₃ nanosheets exhibited an excellent rate capability and cycling performance as an anode material in lithium ion batteries (LIB), as well as a high reversible capacity of 850 mA h g⁻¹ at a current density of 200 mA g⁻¹, which is the highest capacity reported for Cr₂O₃ anode materials.