Activated Carbon Prepared from Alternanthera philoxeroides Biomass by One-step K2CO3 Activation

Abstract

Activated carbons (ACs) were prepared from Alternanthera philoxeroides (AP) by K2CO3 one-step mixing activation. The effects of the mixing mass ratio of K2CO3 to AP, activation temperature, N2 flow rate, and period on the yield and specific surface area of ACs were investigated. The results showed that the surface area and pore volume of ACs were closely related to activation conditions and that the activation temperature was the main factor influencing the surface area and pore volume. The activation conditions only had a slight effect on the yield of ACs, which varied between 13.5% and 19.5%. The surface area of 1799.8 m2/g was obtained at a K2CO3 to AP mass ratio of 2:1, activation temperature of 900 °C, activation time of 2 h, and N2 flow rate of 60 cm3/min. The surface morphology of ACs were characterized with scanning electron microscopy (SEM), and the recovered K2CO3 was characterized with powder X-ray diffractometry (XRD). The SEM images of the ACs also showed that the activation temperature had an obvious effect on the porous structure.