Please use this identifier to cite or link to this item:
Title: Control of Photoactivity over Polycrystalline Anatase TiO 2 Thin Films via Surface Potential
Authors: Ong, S. W. Daniel
Lin, Jianyi
Seebauer, Edmund G.
Keywords: Polycrystalline materials
Surface defects
Issue Date: 2015
Source: Ong, S. W. D., Lin, J., & Seebauer, E. G. (2015). Control of Photoactivity over Polycrystalline Anatase TiO 2 Thin Films via Surface Potential. The Journal of Physical Chemistry C, 119(48), 27060-27071.
Series/Report no.: The Journal of Physical Chemistry C
Abstract: The utility of thin-film TiO2 for photocatalysis would be greatly improved if the spatial variation of the electronic band edges near the surface could be engineered a priori to control the current of photogenerated minority carriers. The present work demonstrates such a concept. In particular, remote oxygen plasma treatment of polycrystalline anatase TiO2 with specified majority carrier concentration is employed in the test case of methylene blue photodegradation. The photoreaction rate varies by up to 35% in concert with a 0.4 eV change in built-in surface potential measured by photoelectron spectroscopy. The correlation between these changes agrees quantitatively with a photodiode–photocurrent model. The plasma treatment affects concentration of charged native defects within the first few atomic layers of the surface, most likely by lowering the concentration of oxygen vacancies within surface crystallites. In tandem, the position in the deep bulk is controlled via engineering the defect concentration at grain boundaries, thus illustrating the coordinated use of multiple defect engineering practices in polycrystalline material to accomplish quantitative manipulation of band bending and corresponding photocurrent.
ISSN: 1932-7447
DOI: 10.1021/acs.jpcc.5b09272
Research Centres: Energy Research Institute @ NTU (ERI@N) 
Rights: © 2015 American Chemical Society. This paper was published in The Journal of Physical Chemistry C and is made available as an electronic reprint (preprint) with permission of American Chemical Society. The published version is available at: One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper is prohibited and is subject to penalties under law.
Fulltext Permission: open
Fulltext Availability: With Fulltext
Appears in Collections:ERI@N Journal Articles

Citations 50

Updated on Sep 18, 2023

Web of ScienceTM
Citations 20

Updated on Sep 22, 2023

Page view(s)

Updated on Sep 23, 2023

Download(s) 20

Updated on Sep 23, 2023

Google ScholarTM




Items in DR-NTU are protected by copyright, with all rights reserved, unless otherwise indicated.