Synthesis of nitrogen-doped carbon spheres using the modified Stöber method for supercapacitors

Nitrogen-doped carbon spheres (NCSs) with uniform and regular morphology were facilely prepared by the modified Stöber method. Hexamethylenetetramine (HMT) was selected as the starting material, which decomposed to provide nitrogen and carbon sources for the synthesis of NCSs. The decomposition product formaldehyde polymerized to form carbon skeleton with resorcinol after carbonization, and the in-situ nitrogen doping was achieved with the decomposed nitrogen source. NCSs were obtained with regular spherical morphology, high specific surface area, and suitable nitrogen doping. When used as the electrode material, NCSs exhibited good capacitance and electrochemical stability, indicating that NCSs be the promising candidate for the electrode material of high-performance supercapacitors.