Facile synthesis of nitrogen-doped porous carbon for supercapacitors

Abstract

A very simple, activation-free method for preparing nitrogen-doped porous carbon with high surface area for supercapacitors by direct pyrolysis of a nitrogen-containing organic salt, ethylenediamine tetraacetic acid (EDTA) disodium magnesium salt, in an inert atmosphere is presented. As the pyrolysis temperature increases from 500 to 900 °C, both the BET surface area and pore volume of the disodium magnesium EDTA-derived carbons increase and reach up to 1811 m² g⁻¹ and 1.16 cm³ g⁻¹, respectively, while the nitrogen content decreases from 11.14 at.% to 1.13 at.%. The carbon obtained at a moderate pyrolysis temperature of 700 °C possesses a balanced surface area (1258 m² g⁻¹) and nitrogen content (5.43 at.%), exhibits high capacitance (281 F g⁻¹), good rate capability (196 F g⁻¹ at 20 A g⁻¹) and cycle durability in 6 mol L⁻¹ KOH aqueous electrolytes.