produced the activated carbon derived from saw dust by treating with 85% solution of H3PO4 in the weight ratio of 1:4.8 at 500 °C for 1.5 hours . The prepared SD-AC attained the specific capacitance of 244.1 F g -1 at 1 A g -1 in 3 M KOH solution with 87% of retention of capacitance after 10000 cycles at 10 A g -1 . Furthermore, the SD-AC based symmetric supercapacitor achieved an energy density of 19.9 Wh Kg -1 along with 80% retention of capacitance after 10000 cycles at 10 A g -1 . It was shown that both SBET of 621 m 2 g -1 along with presence of oxygen and nitrogen functionalities are found to be possible reasons for the and SC-700dtermined from the GCD curve at 0.5 A g -1 in 6 M KOH aqueous solution found to be 263, 172 and 125 F g -1 , respectively. It was also reported that both SC-Zn-700 and SC-Mg-700 displayed the high MB adsorption capacity owing to oxygen rich negative surfaces.