Large surface area hierarchically nanoporous activated carbons are prepared by KOH activation and high temperature carbonization of agricultural waste, Phoenix dactylifera (date) seeds. The nanoporous activated carbon obtained by this method has excellent surface porosity with very large surface area, typically 2383.2 m2 g−1, and large pore volume (1.76 cm3 g−1) due to their interconnected micro- and mesoporous structure. The hierarchically nanoporous material of this activated carbon leads to excellent electrochemical charge storage capability for their application as supercapacitor electrode materials. In a three-electrode cell, an optimum carbon sample exhibited high specific capacitance ca. 386 F g−1 at a current density of 1 A g−1 with excellent retention of specific capacitance (63%) at a very high current density of 50 A g−1. Cyclic stability is also excellent with 98% specific capacitance retention after 10,000 charge-discharge cycles. These hierarchical nanoporous activated carbons derived from agricultural waste materials have sufficient potential for use as electrode materials in commercial, and advanced supercapacitors.

Activated carbons were prepared from date seed powder by chemical activation method using potassium hydroxide (KOH)as activating agent at different temperatures (400, 500, 600 and 700 °C). Date seed powder was impregnated with KOH (1:1weight ratio) and carbonizations were carried out under a constant flow of nitrogen (120 cc/min) in a tubular furnace. The activated carbons thus obtained were characterized by powder X- Ray diffraction and Raman scattering. XRD patterns revealed amorphous carbon structure, which was further confirmed by the Raman scattering. Surface morphology of ACs was studied by scanning electron microscopy (SEM). Date seed derived activated carbons showed good iodine adsorption properties giving iodine number value of 850mg/g, which is much higher than the commercial activated carbons. Therefore, KOH activated date seed derived carbons would have potential in dye adsorption and waste water treatments.

In this work, nanoporous activated carbons from Peach Stone powder was achieved using phosphoric acid as an activating agent and carbonization has been conducted at temperatures ranging from 400oC to 700oC using Nitrogen as inert gas in a tubular furnace, to understand the effect of the adsorption capacity with variation in temperature. Evaluation of microporosity of each of these specimens was performed by Iodine Number technique, of which the results showed a maximum amount of micropores in the carbon at the carbonization temperature of 500oC. The morphology of the carbon samples at two extreme temperatures of 400oC and 700oC was studied using FE-SEM images, which demonstrated large amount of nanoporous in the carbon surfaces at the higher temperature. Raman Spectroscopy outcomes delineate the similar amorphous nature of the carbonaceous specimen at these temperatures with both G band and D band. These results indicate a potential to develop a good adsorbent material applicable for water purification.