Activated carbons from common nettle as potential adsorbents for CO₂ capture

Activated carbons (ACs) prepared from common nettle (Urtica Dioica L.) were studied in terms of carbon dioxide adsorption. ACs were prepared by KOH chemical activation in a nitrogen atmosphere at temperatures (ranging from 500 to 850°C). The pore structure and the surface characterization of the ACs were specified based on adsorption-desorption isotherms of nitrogen measured at –196°C and carbon dioxide at 0°C. The specific surface area was calculated according to the BET equation. The pore volume was estimated using the DFT method. The highest values of the specific surface area (SSA) showed activated carbons produced at higher carbonization temperatures. All samples revealed presence of micropores and mesopores with a diameter range of 0.3–10 nm. The highest value of the CO₂ adsorption, 4.22 mmol/g, was found for the material activated at 700°C.