Density Functional Theoretical Study on the Mechanism of Adsorption of 2-Chlorophenol from Water Using γ-Fe 2 O 3 Nanoparticles

Using density functional theory, the mechanism of adsorption of 2-chlorophenol from water in the presence of γ-Fe₂O₃ nanoparticles was investigated. Fe₂O₃ nanoparticles were modelled using Fe₆(OH)₁₈(H₂O)₆ ring clusters. 2-chlorophenol can coordinate to the γ-Fe₂O₃ nanoparticles via its own OH or Cl groups. The process produces two intermediates which will be converted into final products through two pathways (Cl pathway and OH pathway). The activation energy and activation Gibbs free energy of the two pathways have been calculated and compared with each other. It was found that the OH pathway is under thermodynamic control and the C1 pathway is under kinetic control. All of the calculations were performed using a hybrid density functional method (B3LYP) in the solution phase (PCM model).