Development of modified mesoporous carbon (CMK-3) for improved adsorption of bisphenol-A

Abstract

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 m(2) 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 pi-pi 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. (C) 2019 Published by Elsevier Ltd.