Preparation and characterization of highly surface area activated carbons followed type IV from marine red alga (Pterocladia capillacea) by zinc chloride activation

Activated carbon materials with high specific surface area have been produced from red alga Pterocladia capillacea using zinc chloride as an activating agent at impregnation ratio 0.5 and carbonization temperature that ranged from 500 to 900 °C. The effects of activation temperatures, activation holding time, and soaking in different concentrations of HCl on the specific surface area, pore morphology, and activated carbon yield were tested. A high specific surface area for activated carbon was achieved under the optimized conditions of activation temperature 600 °C, holding time 30 min, and 1 M HCl soaked. The obtained Brunauer–Emmett–Teller surface area, total pore volume, and mean pore diameter were 1202.70 m 2 /g, 0.5797 cm 3 /g, and 1.93 nm, respectively. The prepared activated carbon surface area analysis showed mainly type IV shape. Examination of the morphology of produced activated by scanning electron microscopy and transmission electron microscope revealed a honeycomb morphology and proved the presence of micropores. The adsorption properties toward iodine removal were 86.54% with 0.25 g, and the maximum capacity of methylene blue was 185.23 mg/g indicating a higher surface area and the presence of largely micro- and mesoporous structures.