Activated carbon derived from rice husk by NaOH activation and its application in supercapacitor

Four activated carbon (AC) samples prepared from rice husk under different activation temperatures have been characterized by N₂ adsorption–desorption isotherms, thermogravimetric analysis (TGA–DTA), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The specific surface area of AC sample reached 2681 m² g^?1 under activation temperature of 800 °C. The AC samples were then tested as electrode material; the specific capacitance of the as-prepared activated carbon electrode was found to be 172.3 F g^?1 using cyclic voltammetry at a scan rate of 5 mV s^?1 and 198.4 F g^?1 at current density 1000 mA g^?1 in the charge/discharge mode.