Preparation and characterization of carbonaceous materials containing nitrogen as electrochemical capacitor

Carbonaceous materials containing nitrogen (C/N materials) were prepared by a pyrolysis of 2,3,6,7-tetracyano-1,4,5,8-tetraazanaphthalene (CAN). A C/N material prepared by the pyrolysis of CAN at 1070 K (CAN-1070 K) had a C/N atomic ratio of 3.0 and a non-crystalline carbonaceous structure with a BET surface area of 880 m(2) g(-1). The material CAN-1070 K showed large capacitances of 160-180 F g(-1) and 110-120 F cm(-3) in case of current density of 10 mA cm(-2) (2 A g(-1)) by using three-electrode cell in 1 M H2SO4 aqueous solution, in comparison with that of activated carbon (160 F g(-1) and 55 F cm(-3)) having BET surface area of 2300 m(2) g(-1). ESCA study indicated that pyridinic and quarternary nitrogen atoms existed in the C/N materials, which could result in producing a pseudo-capacitance in addition to the electric double layer capacitance. Also introduction of nitrogen into the carbonaceous material could enhance the wettability of material, which might also improve the capacitance. (C) 2007 Elsevier B.V. All rights reserved.