Insights into the adsorption of organic molecules on rutile TiO₂ (1 1 0) surface: A theoretical study

Abstract

We investigated the adsorption of formic, acetic, benzoic acids, phenol, nitrobenzene molecules on rutile-TiO₂ (1 1 0) surface using the density functional theory (DFT) calculations. Details of the interaction between the investigated molecules and rutile-TiO₂ (1 1 0) surface were thoroughly considered by using the charge transfer and atoms in molecules analyses. The most stable configurations have been found upon adsorption of these molecules on TiO₂ surface by employing the Perdew-Burke-Ernzerhof (PBE) functional and projector-augmented wave method approach and utilizing the periodic slab model. The adsorption processes are determined to be strong chemisorptions, characterized by high adsorption energies in the range of -18.5 to -28.8 kcal.mol⁻¹. Stability of the adsorption eonfigurations is significantly contributed by attractive Ti...O electrostatic interaction and O-H...O strong hydrogen bond. The interactions between the adsorbed molecules on the rutile-TiO₂ (1 1 0) surface are stronger for the >COOH groups than for-OH or NO₂ groups. The results show that the TiO₂-rutile is regarded as a potential adsorption material and an efficient photocatalyst for removal of these organic compounds.