Nitrogen-doped hollow carbon spheres with tunable shell thickness for high-performance supercapacitors.

Nitrogen-doped hollow carbon spheres (NHCSs) are well prepared by using CuO microspheres as a hard template and 3-aminophenol formaldehyde resin polymer as carbon and nitrogen precursors. The thickness of the carbon shell can be easily controlled in the range of 15-84 nm by simply adjusting the weight ratios of the precursors to CuO microspheres, and the CuO templates can also be further reused. Physicochemical characterization demonstrates that the obtained NHCSs possess a well-developed hollow spherical structure, thin carbon shell and high nitrogen doping content.