Regensburg 2019 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

O: Fachverband Oberflächenphysik

O 55: Metal Oxide Surfaces III: Adsorption and Reactivity

O 55.2: Vortrag

Mittwoch, 3. April 2019, 15:15–15:30, H5

Carboxylic acids on magnetite surfaces: insights from DFT — •Kai Sellschopp¹, Björn Arndt^2,3, Marcus Creutzburg^2,3, Heshmat Noei², Andreas Stierle^2,3, Stefan Müller¹, and Gregor Vonbun-Feldbauer¹ — ¹Institute of Advanced Ceramics, Hamburg University of Technology — ²DESY NanoLab, Deutsches Elektronensynchrotron, Hamburg — ³Physics Department, Hamburg University

Magnetite (Fe₃O₄) is a versatile material with applications ranging from catalysis over decontamination of water to hybrid materials made from magnetite nanoparticles with organic linker molecules.^1,2 The structure of and interaction with the major surfaces of magnetite plays a crucial role in most of these applications. In this presentation recent work on the adsorption of organic acids at the magnetite (001) and (111) surfaces studied with density functional theory (DFT) is shown. The mechanism behind the structural change of the magnetite (001) surface upon exposure to formic acid is elucidated from a thermodynamics point of view and by comparison to experimental data from surface X-ray diffraction (SXRD). Calculating the vibrational modes, we find that this structural change in turn also affects the vibrational spectrum of the molecule adsorbed at the surface, which also fits to infrared spectroscopy data. Finally, first results on the adsorption of formic acid at the magnetite (111) surface are shown.
[1] G. Parkinson, Surf. Sci. Rep. 71, 272-365 (2016)
[2] A. Dreyer et al., Nature Materials 15, 522-528 (2016)