Owing to their unique electronic properties and capability to host diverse functional groups on the surface, carbon dots (CDs) have attracted increasing attention in energy storage field. Herein, ultrathin nitrogen-doped carbon dots (NCDs) decorated nickel hydroxide (Ni(OH)2) nanosheets were fabricated by a facile hydrothermal approach, where NCDs play an important role as a structure-directing agent in tuning the size and thickness of the Ni(OH)2. With the merits of the battery-type faradaic behavior of Ni(OH)2 and high electronic properties of NCDs, the achieved Ni(OH)2/NCDs ultrathin nanosheets show a specific capacitance of about 1711.2 F g-1 at a current density of 1 A g-1, which istwice morethan that of pristine Ni(OH)2. A hybrid supercapacitor device was constructed using Ni(OH)2/NCDs ultrathin nanosheets as the positive electrode and three-dimensional graphene (3DGE) as the negative electrode, respectively, which presents high energy density of 23.8-34.6 Wh kg-1 at power density of 700-7000 W kg-1. The enhanced electrochemical properties of Ni(OH)2/NCDs nanocomposite hold potential for future high-performance energy storage applications.
Keywords: Carbon dots; Nickel hydroxide; Supercapacitor; Synthesis; Two-dimensional nanostructures.
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