Facile Synthesis of Mesoporous Activated Carbons Based on Ash Tree for Methylene Blue Adsorption: Mechanism, Kinetics, Isotherm, and Thermodynamic Studies

Abstract

Activated carbons(AC) were synthesized as a result of chemical activation with ZnCl2, NaOH, H3PO4, and H3BO3 from the ash tree(AH), which is abundant in Turkey and the world. It was investigated that the obtained ACs could be used as effective adsorbents for the removal of methylene blue(MB) from the aqueous solution. SEM, EDX, BET, FTIR, and CHNS elemental analyses were used for the characterization of raw and ACs. The results show that carbonaceous materials contain both mesoporous and active functional groups. The maximum adsorption capacities obtained as a result of chemical activation of ZnCl2 (AH-ZnCl2) and NaOH (AH-NaOH) with the best surface area values were determined as 334 mg g(-1) and 364 mg g(-1), respectively. The adsorption mechanism was evaluated with pseudo-first-order and pseudo-second-order kinetic models. It can be concluded that ACs prepared from ash wood are quite ideal when compared with different adsorbents in the literature for removing methylene blue from aqueous solutions.