Nanoporous graphitic carbon materials: Systematic incorporation of p-/m-/o-nitroaniline as effective redox additives for largely improving the capacitive performance

Abstract

In present work, we demonstrate a synchronous carbonization and graphitization process to produce nanoporous graphitic carbon materials, using glucose as carbon source, and Ni-Dimethylglyoxime-complex, Ni(dmgH)2, as graphitization agent. The carbon samples exhibit good graphitic feature at the low carbonization temperature of 800 °C, with the BET surface area of 584 m2 g−1, and pore volume of 0.76 cm3 g−1, and it reveals that increasing the temperature to 900 or 1000 °C can largely enhance the graphitization degree but also decrease the porosity. More importantly, p-/m-/o-nitroaniline as novel redox additives that can easily release electrons/protons have been incorporated into KOH electrolyte to elevate the capacitances, in which the concentration plays a crucial role in determining the electrochemical performance. Besides, the PNA-0.15 sample that fixing p-nitroaniline as 0.15 mmol in 6 mol L−1 KOH electrolyte can deliver a large capacitance of 289 F g−1, which is almost the 1.67 times higher than the pristine one without any redox additive (173 F g−1). In addition, the electrochemical tendency of nitroaniline is of p-nitroaniline > o-nitroaniline > m-nitroaniline, but all of the samples after the incorporation with redox additives exhibit higher electrochemical performance than that of the blank sample.