Understanding Surface Reactivity of Amorphous Transition-Metal-Incorporated Aluminum Oxide Thin Films

The electronic structure of multimetal, amorphous oxides can be varied across a wide range of elemental compositions. Bulk properties such as conductivity, work function, and absorption can thus be tailored to suit a range of applications spanning from carrier-selective contacts to catalysis. Missin...

Ausführliche Beschreibung

Gespeichert in:
Bibliographische Detailangaben
Veröffentlicht in:Journal of Physical Chemistry C 2019-11, Vol.123 (44), p.27048-27054
Hauptverfasser: Stoerzinger, Kelsey A, Enman, Lisa J, Cochran, Elizabeth A, Diulus, J. Trey, Frederick, Ryan T, Artyushkova, Kateryna, Crumlin, Ethan J, Herman, Gregory S, Boettcher, Shannon W
Format: Artikel
Sprache:eng
Online-Zugang:Volltext
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
Beschreibung
Zusammenfassung:The electronic structure of multimetal, amorphous oxides can be varied across a wide range of elemental compositions. Bulk properties such as conductivity, work function, and absorption can thus be tailored to suit a range of applications spanning from carrier-selective contacts to catalysis. Missing, however, is an understanding of how the surface reactivity is impacted in mixed metal-oxide amorphous films. Here we investigate the propensity of Al(1–x) M (x)O y (M = Fe, Mn) amorphous oxide films to dissociate water into hydroxyl groups in a humid environment and find comparable hydroxylation at the low relative humidity (∼0.3% RH) probed by ambient pressure X-ray photoelectron spectroscopy. In contrast, films with both Al and Fe show an increased formation of methoxy groups upon methanol exposure compared to pure Al- and Fe-oxide end members, indicating that the coordination environment of the amorphous oxide network impacts the acidity and redox character of surface metal and oxygen sites. These results provide guidance for the rational design of amorphous oxide layers with tailored chemical reactivity or passivity for a given application.
ISSN:1932-7447
1932-7455
DOI:10.1021/acs.jpcc.9b08227