Controlled synthesis of mesoporous nitrogen-doped carbons with highly ordered two-dimensional hexagonal mesostructures and their chemical activation.

Ordered mesoporous nitrogen-doped carbon (OMNC) materials are considered as the most promising material for supercapacitors. In this study, a highly ordered two-dimensional (2D) hexagonal mesostructured polymer was synthesized through a facile assembly of triblock polymer micelles and phenol-melamine/formaldehyde resin via an organic-organic assembly process in aqueous solution. After calcination, the novel OMNC materials with 2D hexagonal mesostructures were obtained. By further KOH activation, the surface area and the porosity of the OMNC significantly improved, and the internal mesoporous structures were maintained. The activated OMNC-800A displayed a specific capacitance as high as 475.75 F g-1 at 0.5 A g-1 with an outstanding cycling stability (over 100% capacitance retention during 2000 cycling tests at 100 mV s-1). These results confirm that the tubular mesochannels inside the OMNC are very beneficial in providing an accessible path for diffusion of the electrolyte, thereby improving the specific capacitance of OMNC at a high current density.