Interconnected meso/microporous activated carbons were prepared from pumpkin seeds
using a simple chemical activation method. The porous carbon materials were prepared
at different temperatures (PS-600, PS-700, PS-800, and PS-900) and demonstrated huge
surface areas (645–2029 m2 g–1) with excellent pore volumes (0.27–1.30 cm3 g–1). The wellcondensed
graphitic structure of the prepared activated carbon materials was confirmed by
Raman and X-ray diffraction analyses. The presence of heteroatoms (O and N) in the carbon
materials was confirmed by X-ray photoemission spectroscopy. High resolution transmission
electron microscopic images and selected area diffraction patters further revealed the porous
structure and amorphous nature of the prepared electrode materials. The resultant porous
carbons (PS-600, PS-700, PS-800, and PS-900) were utilized as electrode material for
supercapacitors. To our delight, the PS-900 demonstrated a maximum specific capacitance
(Cs) of 303 F g–1 in 1.0 M H2SO4 at a scan rate of 5 mV. The electrochemical impedance
spectra confirmed the poor electrical resistance of the electrode materials. Moreover, the
stability of the PS-900 was found to be excellent (no significant change in the Cs even after
6000 cycles).