Interaction of organic pollutants with TiO₂: a density functional theory study of carboxylic acids on the anatase (101) surface

Understanding the interaction of carboxylic group with TiO2 is crucial for photocatalytic degradation pollutants, because aromatic molecules containing acid groups are among most common micropollutants. This study investigated interactions anatase (101) surface several acids: benzoic, nicotinic, salicylic and anthranilic acid, using dispersion-corrected density functional theory (DFT) calculations. For all studied, we found higher stabilities monodentate adsorbed configurations over bidentate. Dispersion was to have a significant effect on adsorption energies. In particular, dispersion gave rise tilted configuration, where through interfacial covalent hydrogen bonds additionally stabilised by ring surface. Comparative calculations DFT empirical correction van der Waals-corrected functionals relative structures be independent method describing dispersion. Thermodynamic probabilities different were evaluated Boltzmann distribution, dispersion-stabilised predicted far abundant. Finally, optical absorption TiO2-acid systems modelled, TiO2-aromatic complexes their extended into visible range.