Synthesis and characterization of chemically activated carbon from Passiflora ligularis, Inga feuilleei and native plants of South America

Activated carbons (ACs) play a key role in applications such as treatment and purification of water and polluting gases and new application as supercapacitators. The present work is related to the synthesis of new green adsorbents from the seeds and shells of Inga feuilleei and Passiflora ligularis, wood of Kageneckia lanceolata, Baccharis salicifolia and Baccharis latifolia. Both the porous texture and adsorption capacity of the new activated carbon were studied. The ACs were synthesized by conventional chemical activation using phosphoric acid. Results indicated that each synthesized AC presented a microporous/mesoporous texture and the three best iodine numbers obtained were 978.55, 905.8 and 865.9 mg.g(-1). These results were achieved for the ACs from Passiflora ligularis, Kageneckia lanceolata and Baccharis salicifolia, respectively. The optimal conditions to achieve the best iodine number (978.55 mg.g(-1)) and BET surface area (1244.62 m(2). g(-1)) were found for the Passiflora ligularis, at carbonization temperature of 500 degrees C, for 120 min, impregnation ratio of 1:4 (raw material/H3PO4) and concentration of activating agent H3PO4 of 60 %. The FT-IR spectroscopy method was used to characterize the functional groups present on the surface of the AC and the raw materials. On the other hand, the TGA analysis was carried out to show the AC mass loss as the temperature increased. Both analyzes showed that the activation was fully achieved under the optimal conditions described above. The results confirmed that the shell of Passiflora ligularis is a promising material as a highly adsorptive, low cost and renewable adsorbent.