Modeling the physisorption of bisphenol A on graphene and graphene oxide

Abstract

The physisorption of bisphenol A (BPA) on pristine and oxidized graphene was studied theoretically via calculations performed at the PBE-D3 level (including dispersion force corrections). Three stable conformations of BPA on graphene were found. A lying-down configuration was energetically favored because the presence of π-π stacking and dispersion forces increased interactions. In addition, the adsorption of BPA on the edges of graphene oxide was enhanced when adsorption occurred on carboxyl and carbonyl groups, whereas the adsorption strength decreased when adsorption occurred on hydroxyl groups. The highest physisorption strength was obtained on the surface of graphene oxide due to the presence of π-π stacking and dispersion forces (which provided the greatest contribution to the adsorption energy) as well as hydrogen bonds (which provided a smaller contribution), indicating that oxidized graphene is a better candidate than pristine graphene for BPA removal. On the other hand, an increase in electrophilicity was observed after the physisorption of BPA in all systems (with respect to graphene and BPA in their isolated forms), with the adsorbent acting as the electron acceptor. Finally, molecular dynamics simulations performed using the PM6 Hamiltonian showed that the adsorption of BPA on graphene is stable.

Characteristic Evaluation of Graphene Oxide for Bisphenol A Adsorption in Aqueous Solution

“…Additionally, since the length of BPA molecule is 0.94 nm and the average pore size of GO varies in the range from 2.3 to 5 nm, this pore size is sufficient for the BPA molecules to enter and be adsorbed on the adsorption sites [28,44,45]. The high performance of GO is confirmed not only by these explanations, but also by some previous computational studies [9,10]. The adsorption energy of BPA onto GO obtained by the DFT study is higher than that onto graphene.…”

“…Cortés-Arriagada et al [9] investigated the adsorption of BPA on graphene and GO using the density functional theory (DFT) method. At the basal plane of GO, the highest adsorption energy was obtained from the binding between BPA and hydroxyl groups.…”

Aluminum and iron doped graphene for adsorption of methylated arsenic pollutants

“…Hamiltonian implemented in the MOPAC2012 program [62]; we have successfully used this methodology to analyze the stability onto graphene of 4chlorophenol [63], bisphenolA [64] and inorganic trivalent arsenic (iAs III ) [20]. The time-step for all the simulations was of 0.5 fs, and 5.0 ps were used in the production step; data were collected for statistics after 1.0 ps of both heating and equilibrium steps.…”

Effects of temperature on adsorption and oxidative degradation of bisphenol A in an acid-treated iron-amended granular activated carbon

“…Adsorption and advanced oxidation are among various remediation options considered to be effective treatment methods to remove BPA from wastewater and water sources [14][15][16][17][18][19][20]. Adsorption is simple and effective, but it requires high operating costs associated with the regeneration of contaminant-spent adsorbents (i.e., activated carbon) [21,22].…”