Controlled synthesis of N-doped carbon spheres with different morphologies for supercapacitors

Abstract

A facile and general strategy has been developed for synthesizing nitrogen doped mesoporous carbon nanospheres (NMCs), newly nitrogen doped lychee exocarp-like mesoporous carbon spheres (NLEMCs) and nitrogen doped core–shell mesoporous carbon spheres (NCSMCs). In this soft templating strategy, cetyltrimethylammonium chloride is used as the template while m-aminophenol is employed as a nitrogen source. All three types of N-doped carbon nanospheres, with uniform spherical morphologies, abundant mesoporous structures, high N-doped content, high surface areas and large pore volumes, exhibit specific capacitances of 262.4 F g⁻¹, 323.2 F g⁻¹ and 247.06 F g⁻¹, respectively, at a current density of 0.2 A g⁻¹ in 6 M KOH electrolyte solution. NLEMCs with a new lychee exocarp-like spherical morphology show an excellent electrochemical performance as a supercapacitor electrode, which may be due to there being more active sites, caused by the high surface area.