Adsorption of glyphosate on graphene and functionalized graphenes: A DFT study

The systems under study show promise for further studies and possible application as glyphosate trapping agents. • Nine graphene systems with different organic moieties (CO, COOH, OH, O and SH) as glyphosate adsorbents was determined. • The systems with the highest adsorption capacities were those with the alcohol, acid, epoxide and thiol substituents. • The stability of the interaction is mainly given by hydrogen bonds but classical molecular dynamics studies suggest the importance of Van der Waals forces in the adsorption phenomenon at 298.15 K. • The systems under study show promise for further studies and possible application as glyphosate trapping agents. A study was carried out under the framework of density functional theory where the adsorption capacity of nine graphene systems with different organic moieties (CO, COOH, OH, O and SH) as glyphosate adsorbents was determined. The systems with the highest adsorption capacities were those with the alcohol, acid, epoxide and thiol substituents, according to energetic parameters such as interaction energy, enthalpy and Gibbs free energy of adsorption. The stability of the interaction is mainly given by hydrogen bonds, which was corroborated by the study of the bond critical points, as well as the index of non-covalent interactions. However, classical molecular dynamics studies suggest the importance of Van der Waals forces in the adsorption phenomenon at 298.15 K. The systems under study show promise for further studies and possible application as glyphosate trapping agents.