Water-induced reversal of the TiO2 (011)-(2x1) surface reconstruction: observed with in situ surface X-ray diffraction

DOI: 10.1021/acs.jpcc.9b04383

Authors: Hadeel Hussain (The University of Manchester) , Mahmoud H. M. Ahmed (The University of Manchester) , Xavier Torrelles (Institut de Ciència de Materials de Barcelona (CSIC)) , David Grinter (University College London) , Gregory Cabailh (Sorbonne Université, UMR CNRS 7588) , Oier Bikondoa (ESRF, The European Synchrotron; University of Warwick) , Christopher Nicklin (Diamond Light Source) , Ulrich Aschauer (University of Bern) , Robert Lindsay (The University of Manchester) , Geoff Thornton (University College London)
Co-authored by industrial partner: No

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

State: Published (Approved)
Published: May 2019
Diamond Proposal Number(s): 8952

Abstract: The (011) termination of rutile TiO2 is reported to be particularly effective for photocatalysis. Here the structure of the interface formed between this substrate and water is revealed using surface X-ray diffraction. While the TiO2(011) surface exhibits a (2x1) reconstruction in ultra-high vacuum, this is lifted in the presence of a multilayer of water at room temperature. This change is driven by the formation of Ti-OH at the interface, which has a bond distance of 1.93 ± 0.02 Å. The experimental solution is in good agreement with density functional theory and first principles molecular dynamics calculations. These results point to the important differences that can arise between the structure of oxide surfaces in ultra-high vacuum and technical environments and will ultimately lead to an atomistic understanding of the photocatalytic process of water splitting on TiO2 surfaces.

Subject Areas: Chemistry, Materials


Instruments: I07-Surface & interface diffraction