Facile Synthesis of Poly(p‑phenylenediamine)-Derived Three-Dimensional Porous Nitrogen-Doped Carbon Networks for High Performance Supercapacitors

We introduce a facile integrated oxidation polymerization and catalytic carbonization method to prepare three-dimensional porous nitrogen-doped carbon networks (3D N-CNWs) with high nitrogen content (about 8.4 wt %) directly from poly(p-phenylenediamine). In the synthesis process, the FeCl3 serves not only as an oxidant for oxidative polymerization of p-phenylenediamine monomers but also as the carbonization catalyst to promote porous carbon network formation. The 3D N-CNWs prepared at 700 °C exhibit an interconnected porous framework with high specific surface area and show remarkable performance as an electrode material for supercapacitors. The maximum specific capacitance of 304 F g–1 at a current density of 0.5 A g–1, which retains the high values of 226 F g–1 even at a high current density of 20 A g–1, is obtained for the N-CNW electrode in 6 M KOH aqueous solution. Moreover, the as-assembled N-CNW symmetric supercapacitor exhibits a considerably high energy density of 15.8 Wh kg–1 at a power density of 450 W kg–1 operated in the voltage range 0–1.8 V in 0.5 M Na2SO4 aqueous solution, and exhibits an excellent cycling performance with 97% specific capacitance retention after 5000 cycles.