Controlled Synthesis of a Hierarchically Porous N-Doped Carbon Material with Dominantly Pyrrolic Nitrogen Using a Self-Sacrificial SBA-15 Template for Increased Supercapacitance

Herein, we report an effective strategy to synthesise a hierarchically porous pyrrolic nitrogen-dominated doped carbon material (N-doped carbon material) by the low-temperature carbonisation and post-KOH activation of a 3-fluorophenol-3-aminophenol-formaldehyde co-condensed resin using a self-sacrificial SBA-15 template. Low-temperature thermal treatment successfully prevented the transformation of the thermally unstable and pseudocapacitance-active pyrrolic nitrogen to pseudocapacitance-inactive graphitic nitrogen configurations. Additionally, the combined effect of the self-sacrificial SBA-15 template and KOH activation resulted in a high specific surface area of 582 m(2) g(-1) and hierarchical microporous/mesoporous architecture, thereby maximising the exposure of electrochemically active sites. The N-doped carbon material exhibited an outstanding specific capacitance of 532.8 F g(-1) (electrochemical double-layer capacitance of 331.2 F g(-1) and faradaic pseudocapacitance of 201.6 F g(-1)) at a scan rate of 1 mV s(-1) and stability with the retention of nearly 100 % at a current density of 10 A g(-1) after 10000 cycles.