One-pot hydrothermal synthesis of nitrogen-doped hierarchically porous carbon monoliths for supercapacitors

The nitrogen-doped hierarchically porous carbon monoliths (N-HPCMs) were successfully synthesized by using dicyandiamide (DCDA) as nitrogen source, phenolic resol as carbon precursor and mixed triblock copolymers as templates via a one-pot hydrothermal approach. The obtained carbon monoliths possess tunable mesopore size (4.3–11.4 nm), large surface area (552–660 m2/g), and high nitrogen content (up to 12.1 wt%). Ascribed to the nitrogen-doped frameworks and hierarchical porosity, N-HPCMs exhibit good electrochemical performance as the supercapacitor electrode with specific capacitance of 268.9 F/g (in 6 M KOH) at a current density of 1 A/g, and a 4.1 % loss of the specific capacitance after 5,000 charge–discharge cycles, indicating a long-term cycling stability. Such unique features make N-HPCMs promising electrode materials for high performance supercapacitors.