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O: Fachverband Oberflächenphysik
O 5: Adsorption on semiconductors, oxides and insulators I
O 5.6: Vortrag
Montag, 26. März 2012, 11:45–12:00, MA 042
Adsorption of amino acids on the TiO2 (110) surface — •Ralf Tonner — Fachbereich Chemie, Philipps-Universität Marburg, Germany
The optimal adsorption modes for amino acids glycine and proline on the ideal TiO2(110) surface have been investigated using density functional theory (PBE) applying periodic boundary conditions (VASP). Binding modes with anionic acid moieties bridging two titanium atoms after transferring a proton to the surface are the most stable configurations for both molecules investigated similar to previous results for carboxylic acids. In contrast to the latter, amino acids can form hydrogen bonds via the amino group towards the surface-bound proton which provide an additional stabilization of 15-20 kJ mol−1.
Calculations of vibrational frequencies complement the adsorption study and provide guidance for future experimental investigations. Dispersion effects can influence the relative stabilities of adsorption modes considerably.