Highly efficient synthesis of ordered nitrogen-doped mesoporous carbons with tunable properties and its application in high performance supercapacitors

Abstract

Nitrogen-doped ordered mesoporous carbons (OMCs) have been synthesized via aqueous cooperative assembly route in the presence of basic amino acids as either polymerization catalysts or nitrogen dopants. This method allows the large-scale production of nitrogen-doped OMCs with tunable composition, structure and morphology while maintaining highly ordered mesostructures. For instances, the nitrogen content can be varied from ∼1 wt% to ∼6.3 wt% and the mesophase can be either 3-D body-centered cubic or 2-D hexagonal. The specific surface area for typical OMCs is around 600 m2 g−1, and further KOH activation can significantly enhance the surface area to 1866 m2 g−1 without destroying the ordered mesostructures. Benefiting from hierarchically ordered porous structure, nitrogen-doping effect and large-scale production availability, the synthesized OMCs show a great potential towards supercapacitor application. When measured in a symmetrical two-electrode configuration with an areal mass loading of ∼3 mg cm−2, the activated OMC exhibits high capacitance (186 F g−1 at 0.25 A g−1) and good rate capability (75% capacity retention at 20 A g−1) in ionic liquid electrolyte. Even as the mass loading is up to ∼12 mg cm−2, the OMC electrode still yields a specific capacitance of 126 F g−1 at 20 A g−1.