The adsorption of bisphenol-A (BPA) on ordered mesoporous carbon (CMK-3) and modified CMK-3 (MCMK-3) for decontamination of aqueous medium was investigated. The CMK-3 and MCMK-3 materials had uniform pore sizes of 3.60 and 3.70 nm and high Brunauer-Emmett-Teller (BET) surface areas of 751 and 564 m2 g-1, respectively. The maximum adsorption capacities of CMK-3 and MCMK-3 were 178.57 (0.24 mg m-2) and 238.01 (0.42 mg m-2) mg g-1, respectively at 298 K (pH 6.4). The difference in the adsorption capacities is attributed to the specific surface area and hydrophobicity of the adsorbents. The adsorption of BPA on CMK-3 and MCMK-3 may be influenced by π-π bonding and hydrophobic and electrostatic interactions, and the excellent adsorption capacity of MCMK-3 is attributed to its unique sp2-hybridized single-atom-layer structure. The kinetics and isotherm data were described by the pseudo-second order kinetic model and the Langmuir isotherm, respectively. This difference in the adsorption kinetics of CMK-3 and MCMK-3 is caused by the increase in the pore diameter of the latter. Further, CMK-3 and MCMK-3, with an open geometry consisting of interlinked nanorods, allow for faster intraparticle diffusion. Overall, CMK-3 and MCMK-3 could be promising adsorbents for the removal of chemicals containing benzene rings from wastewater.
Keywords: Activation energy; Bisphenol-A; Gigs free energy; Modified CMK-3; Ordered mesoporous carbons CMK-3.
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