Water splitting on Ti-oxide terminated SrTiO3(001)

DOI: 10.1021/acs.jpcc.9b01730

Authors: Vladyslav Solokha (Diamond Light Source; Johannes Kepler Universität Linz) , Debi Garai (Diamond Light Source; Amity University) , Axel Wilson (Diamond Light Source) , David A. Duncan (Diamond Light Source) , Pardeep K. Thakur (Diamond Light Source) , Kurt Hingerl (Johannes Kepler Universität Linz) , Jorg Zegenhagen (Diamond Light Source)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: The Journal Of Physical Chemistry C

State: Published (Approved)
Published: June 2019
Diamond Proposal Number(s): 15132

Abstract: Combining X-ray photoelectron spectroscopy with the standing wave technique we investigated adsorption of a monolayer of water on Ti-oxide terminated SrTiO3(001) in ultra-high vacuum (UHV). At room temperature, the surface is water free but hydroxylated. A quarter monolayer of hydroxyl is tightly bound (1.85 ± 0.06) Å above the TiO2 surface. Deposited at low temperature, a monolayer of water adsorbs with the oxygen located (2.55 ± 0.2) Å above the surface, apparently close to atop Ti, but H2O is unstable at 200K. A fraction desorbs, in part under the X-ray beam, but a major fraction of H2O dissociates immediately, with the liberated hydrogen most likely attaching to a surface oxygen. The produced hydroxyls bind only loosely to the surface, are unstable at 200K and rapidly desorb once the surface is water-free. Although our study was conducted in UHV, the presented results suggests that Ti-oxide terminated SrTiO3(001) may possess a high catalytic activity toward hydrolysis under realistic conditions.

Subject Areas: Chemistry


Instruments: I09-Surface and Interface Structural Analysis

Documents:
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