Anchoring nitrogen-doped carbon quantum dots on nickel carbonate hydroxide nanosheets for hybrid supercapacitor applications.

With the ever-increasing demands for energy resources, the exploration of high energy density hybrid supercapacitors is urgently required. Herein, an effective hydrothermal strategy is demonstrated to construct advanced cathode of nickel carbonate hydroxide (NCH) ultrathin nanosheets anchored nitrogen-doped carbon quantum dots (NCQDs) for hybrid supercapacitors. It is revealed that the NCQDs are evenly deposited on the surface of NCH nanosheets, which provide abundant active sites for NCH nanosheets and endow them improved electrochemical characteristics.

High energy density hybrid supercapacitor based on cobalt-doped nickel sulfide flower-like hierarchitectures deposited with nitrogen-doped carbon dots.

The exploration of advanced electrode materials with outstanding electrochemical properties is of considerable importance for hybrid supercapacitors but challenging. In this paper, an effective two-step solvothermal route is demonstrated to synthesize nitrogen-doped carbon dots (NCDs) decorated cobalt-doped nickel sulfide (Co-NiS) flower-like hierarchitectures. Because of the modification with NCDs and doping by cobalt atoms, the resulting Co-NiS/NCDs hierarchitectures exhibit an ultrahigh specific capacity up to 1240 C g-1 (2480 F g-1) at 1 A g-1 and a remarkable rate capability of 790.

Nitrogen-doped carbon dots anchored NiO/CoO ultrathin nanosheets as advanced cathodes for hybrid supercapacitors.

Herein, we demonstrate an advanced cathode of nitrogen-doped carbon dots (NCDs) anchored NiO/CoO ultrathin nanosheets for hybrid supercapacitors by a facile hydrothermal-calcination route. Owing to the well defined thin-plate structure and ternary composition, the optimized NiO/CoO/NCDs nanosheets demonstrate a high specific capacity of 976.3 C g (1775 F g) at 1 A g, and a splendid cycling stability of approximately 95.