CARBONLETT, vol. 24, no. 1, pp.73-81, 2017

DOI: http://dx.doi.org/10.5714/CL.2017.24.73

Interconnected meso/microporous carbon derived from pumpkin seeds as an efficient electrode material for supercapacitors

Mayakrishnan Gopiraman¹, Somasundaram Saravanamoorthy², Seung-Hyun Kim¹ and Ill-Min Chung^1,â™ 

Affiliation: ¹Department of Applied Bioscience, College of Life & Environment Science, Konkuk University, Seoul 05029, Korea
²Department of Chemistry, National Institute of Technology, Tiruchirappalli 620015, India

Abstract: 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).

Keyword: pumpkin seeds, activated carbon, electrode materials, supercapacitors, cycle stability