Fig nbsp shows the BET specific surface

Fig. 4 shows the BET specific surface area of PSAC at different activation temperatures using fresh and reclaimed H3PO4. The BET specific surface area increases in accordance to the activation temperature of 375–525 °C, with the maximum BET surface area of 2153 m2/g at an activation temperature of 525 °C with fresh H3PO4 acid. As seen from the figure although a highest surface area PSAC is produced at 525 °C, the utilization of reclaimed Sulfo-NHS-SS-Biotin for successive activation significantly reduces the textural characteristics of the carbon. However at temperature range of 375–475 °C, PSAC produced using reclaimed H3PO4 possess an extensive surface area, provided activation is at constant impregnation ratio. PSAC from reclaimed H3PO4 exhibited BET surface area almost similar with the PSAC produced using fresh H3PO4, asserting the functionality of reclaimed acid still intact and not deteriorated with the number of reuse in impregnation-activation. A significant increase in the surface area is observed with increase in the activation temperature up to an activation temperature of 475 °C, with all the subsequent reclaimed runs as well confirming the repeatability of the surface area. The surface area seems to reach a plateau at 475 °C indicating the optimum conditions around 475 °C. Hence the optimum condition for activation has been identified to be an activation temperature of 475 °C, with an impregnation ratio of 1.75, at activation duration of 75 min.