“Dissolution-Capture” Strategy to Form Monodispersed Nitrogen-Doped Hollow Mesoporous Carbon Spheres

Abstract

Monodispersed nitrogen-doped hollow mesoporous carbon spheres (N-HMCSs) have been successfully synthesized using a novel “dissolution-capture” method. The mesoporous silica is uniformly coated on the surface of the polystyrene/polyacrylonitrile composite nanospheres (PS@PAN) core by using a modified Stöber method. Then a hollow cavity is formed through the dissolution of the PS@PAN in organic solvent. The dissolved PS@PAN as the carbon and nitrogen precursor is captured in the mesochannels of the silica shell. The obtained N-HMCSs have high specific surface area of 807 m2 g−1, uniform mesopore size of 4.1 nm, and nitrogen content of 3.6 at.%. In addition, the N-HMCSs show a high specific capacitance of 212 F g−1 at a current density of 1 A g−1 in 6 M KOH electrolyte and capacitance retention of 93.9% after 10000 charge/discharge cycles at 5 A g−1. The “dissolution-capture” method can give a useful enlightenment for the design of electrode materials for supercapacitors.