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GaAs Microisland Anodes Protected by Amorphous TiO₂ Films Mitigate Corrosion Spreading During Water Oxidation in Alkaline Electrolytes

Buabthong, Pakpoom and Evans, Jake M. and Rinaldi, Katherine Z. and Kennedy, Kathleen M. and Fu, Harold J. and Ifkovits, Zachary P. and Kuo, Tai-Jung and Brunschwig, Bruce S. and Lewis, Nathan S. (2021) GaAs Microisland Anodes Protected by Amorphous TiO₂ Films Mitigate Corrosion Spreading During Water Oxidation in Alkaline Electrolytes. ACS Energy Letters, 6 (10). pp. 3709-3714. ISSN 2380-8195. doi:10.1021/acsenergylett.1c01174. https://resolver.caltech.edu/CaltechAUTHORS:20211008-224620533

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Abstract

Microisland structures of ∼200 μm diameter GaAs circles were fabricated and used to spatially isolate defects during electrochemical operation as an anode in aqueous alkaline electrolytes. The microisland structures allowed one to measure the rate and distribution of the pinhole formation on electrodes protected by 110 nm-thick amorphous titanium dioxide (a-TiO₂) films formed by atomic layer deposition. Although no crystalline regions were detected by Raman spectroscopy, a limited number of defects were present in the a-TiO2 layer and developed into new microscopic pinholes within the first 20 h of electrochemical operation. The film dissolved at a rate of <13 nm per day, and hence, intrinsic film dissolution was not the primary mode of pinhole formation during this first 20 h of operation. The fabrication processes presented herein only utilized chemical etching and mechanical polishing and, consequently, should be readily transferable to the fabrication of the more complicated np⁺-GaAs structures.


Item Type:Article
Related URLs:
URLURL TypeDescription
https://doi.org/10.1021/acsenergylett.1c01174DOIArticle
ORCID:
AuthorORCID
Buabthong, Pakpoom0000-0001-5538-138X
Evans, Jake M.0000-0002-8721-5316
Rinaldi, Katherine Z.0000-0002-0746-2852
Kennedy, Kathleen M.0000-0002-7125-4871
Fu, Harold J.0000-0001-9738-209X
Ifkovits, Zachary P.0000-0003-2538-0794
Brunschwig, Bruce S.0000-0002-6135-6727
Lewis, Nathan S.0000-0001-5245-0538
Alternate Title:GaAs Microisland Anodes Protected by Amorphous TiO2 Films Mitigate Corrosion Spreading During Water Oxidation in Alkaline Electrolytes
Additional Information:© 2021 American Chemical Society. Received 7 June 2021. Accepted 20 September 2021. Published online 27 September 2021. Published in issue 8 October 2021. This material is based upon work performed by the Joint Center for Artificial Photosynthesis, a DOE Energy Innovation Hub, supported through the Office of Science of the U.S. Department of Energy under Award Number DE-SC0004993 and under award DE-SC0022087 from the Basic Energy Sciences Office of the DOE. We gratefully acknowledge a gift from the Lam Research Unlock Ideas program. P.B. is grateful to Toy Jatuporn Leksut for assistance with illustrations and visualization of the data. The authors declare no competing financial interest.
Group:JCAP
Funders:
Funding AgencyGrant Number
Department of Energy (DOE)DE-SC0004993
Department of Energy (DOE)DE-SC0022087
Lam Research Unlock IdeasUNSPECIFIED
Subject Keywords:Electrochemistry, Layers, Electrodes, Defects, Gallium arsenide
Issue or Number:10
DOI:10.1021/acsenergylett.1c01174
Record Number:CaltechAUTHORS:20211008-224620533
Persistent URL:https://resolver.caltech.edu/CaltechAUTHORS:20211008-224620533
Official Citation:GaAs Microisland Anodes Protected by Amorphous TiO2 Films Mitigate Corrosion Spreading During Water Oxidation in Alkaline Electrolytes Pakpoom Buabthong, Jake M. Evans, Katherine Z. Rinaldi, Kathleen M. Kennedy, Harold J. Fu, Zachary P. Ifkovits, Tai-Jung Kuo, Bruce S. Brunschwig, and Nathan S. Lewis ACS Energy Letters 2021 6 (10), 3709-3714 DOI: 10.1021/acsenergylett.1c01174
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:111322
Collection:CaltechAUTHORS
Deposited By: George Porter
Deposited On:12 Oct 2021 14:49
Last Modified:12 Oct 2021 14:49

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