An in situ exploration of subsurface defect migration to a liquid water?exposed rutile TiO2(110) surface by XPS

Ahmed, M. H. Mesbah; Temperton, Robert H.; O'Shea, James N.

Abstract

The ability of titanium dioixide to split water into OH? and H+ species is heavily dependent on the behaviour of defects in the crystal structure at or near the surface. We present an in situ study of defect migration in rutile TiO2(110) conducted using X-ray photoelectron spectroscopy (XPS). First, surface and subsurface defects were created in the crystal by argon ion sputtering. Subsequent in situ exposure of the defective crystal to liquid water healed the surface defects, whereas the subsurface remained defective. The sample was then annealed while XPS was used to monitor the concentration of titanium defects. At low annealing temperatures, Ti3+ was observed to migrate from the subsurface to the surface. Further annealing gradually restored the surface and subsurface to the defect-free Ti4+ form, during which the changes in abundance of Ti1+, Ti2+ and Ti3+ defects are discussed.

Citation

Ahmed, M. H. M., Temperton, R. H., & O'Shea, J. N. (2021). An in situ exploration of subsurface defect migration to a liquid water?exposed rutile TiO2(110) surface by XPS. Surface and Interface Analysis, 53(12), 1013-1019. https://doi.org/10.1002/sia.6906

• Journal Article Type: Article
• Acceptance Date: Oct 21, 2020
• Online Publication Date: Nov 16, 2020
• Publication Date: 2021-12
• Deposit Date: Nov 18, 2020
• Publicly Available Date: Nov 19, 2020
• Journal: Surface and Interface Analysis
• Print ISSN: 0142-2421
• Electronic ISSN: 1096-9918
• Publisher: Wiley
• Peer Reviewed: Peer Reviewed
• Volume: 53
• Issue: 12
• Pages: 1013-1019
• DOI: https://doi.org/10.1002/sia.6906
• Keywords: Materials Chemistry; General Chemistry; Surfaces, Coatings and Films; Surfaces and Interfaces; Condensed Matter Physics
• Public URL: https://nottingham-repository.worktribe.com/output/5051401
• Publisher URL: https://onlinelibrary.wiley.com/doi/10.1002/sia.6906