| AVS 65th International Symposium & Exhibition | |
| Surface Science Division | Tuesday Sessions |
| Session SS+HC+MI-TuA |
| Session: | Oxides/Chalcogenides: Structures and Reactions |
| Presenter: | Zdenek Jakub, Vienna University of Technology, Austria |
| Authors: | Z. Jakub, Vienna University of Technology, Austria M. Meier, University of Vienna, Austria J. Hulva, Vienna University of Technology, Austria J. Pavelec, Vienna University of Technology, Austria M. Setvin, Vienna University of Technology, Austria M. Schmid, Vienna University of Technology, Austria U. Diebold, Vienna University of Technology, Austria C. Franchini, University of Vienna, Austria G.S. Parkinson, Vienna University of Technology, Austria |
| Correspondent: | Click to Email |
The interaction between iron oxides and water plays a key role in many natural and technological processes. Recent water adsorption studies have found significant complexity on metal oxides, with reports of mixed-mode adsorption and hydrogen bonding. Here we present a multi-technique study of water adsorption on Fe3O4 surfaces. Utilizing quantitative temperature programed desorption (TPD) and X-ray Photoelectron Spectroscopy (XPS), we identify four partially dissociated phases in the submonolayer regime on the Fe3O4(001), corresponding to coverages of 9, 8, 6 and 3 molecules per surface unit cell. These are investigated by non-contact atomic force microscopy (nc-AFM) with tip functionalized by CO molecule, and the observed structures are further interpreted by DFT-based calculations. We clearly demonstrate the existence of partially dissociated dimers and trimers at lower coverage, and a build-up of complex hydrogen-bonded network with increasing coverage. Applying the same approach on the Fe3O4(111) we discuss the general trends of water adsorption on Fe3O4 surfaces.