Regensburg 2016 – scientific programme

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O: Fachverband Oberflächenphysik

O 26: Oxides and Insulator Surfaces: Adsorption

O 26.2: Poster

Monday, March 7, 2016, 18:15–20:30, Poster E

Dimerization of benzoic acid on TiO₂ surfaces—an ab-initio study — •Wolfgang Heckel, Tim Würger, and Stefan Müller — Hamburg University of Technology, Institute of Advanced Ceramics

At the hybrid organic–metal-oxide interface intermolecular forces may contribute to improving mechanical stability. For instance linker molecules possessing an aromatic side chain interact with each other via van-der-Waals interaction.

In this regard, the adsorption of benzoic acids on TiO₂ (110) rutile serves as a prototype system. A very regular 2×2 overlayer due to dimerization via the phenyl groups has recently been reported [1].

Here, we present a density functional theory analysis of the dimerization of benzoic acids on both, anatase and rutile TiO₂ surfaces. To properly describe the attractive interaction of adsorbing molecules among each other, we applied an exchange correlation functional with van-der-Waals correction. For all surface orientations, the prefered dimer formation mode (hydrogen–to–π-orbital or tilted and twisted π–to–π) as well as the amount of energy gain resulting from dimerization will be discussed.

[1] Grinter et al., J. Phys. Chem. Lett. 5, 4265 (2014).

Supported by DFG, SFB 986, project A4.