A comparative study of one‒step and two‒step activated carbon from longan seeds by dry chemical activation with NaOH

Abstract

This research aims to study the effects of one‒step and two‒step activated carbon from longan seeds by dry chemical activation with NaOH. The longan seeds and their charcoal produced at carbonized temperature of 500 °C, were impregnated by dry chemical activation with NaOH at a weight ratio of 1.00:1.00, 1.00:1.50 and 1.00:2.00 at activation temperatures ranging from 500, 600 and 700 °C for 2 h. The iodine number, surface area, pore volume, functional group, crystalline phases, surface morphology and elemental composition of the activated carbons were examined. The results showed that the two-step process had the highest iodine number and BET surface area of 987.22 mg g^‒1 and 975.18 m² g^‒1, respectively, which is the standard measure for liquid-phase applications.