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Defect-Tolerant TiO₂-Coated and Discretized Photoanodes for >600 h of Stable Photoelectrochemical Water Oxidation

Shen, Xin and Yao, Maoqing and Sun, Ke and Zhao, Tianshuo and He, Yulian and Chi, Chun-Yung and Zhou, Chongwu and Dapkus, Paul Daniel and Lewis, Nathan S. and Hu, Shu (2021) Defect-Tolerant TiO₂-Coated and Discretized Photoanodes for >600 h of Stable Photoelectrochemical Water Oxidation. ACS Energy Letters, 6 (1). pp. 193-200. ISSN 2380-8195. https://resolver.caltech.edu/CaltechAUTHORS:20201217-143607686

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Abstract

Arrays of GaAs nanowires have been grown by selective-area metal–organic chemical-vapor deposition (MOCVD) onto photoactive planar Si substrates. This tandem, vertical-wire-array-on-planar absorber was then coated by atomic layer deposition (ALD) of an amorphous TiO₂ (a-TiO₂) stabilization layer, followed by deposition of a NiO_x electrocatalyst layer. The tandem planar Si/nanowire GaAs/a-TiO₂/NiO_x photoanodes exhibited continuous solar-driven water oxidation in 1.0 M KOH(aq) for over 600 h without substantial photocurrent decay. The preservation of the nanowire morphology and structural integrity during >600 h of photoanodic operation confirms the benefits of mitigating and isolating nanoscale defects via the architecture of discretized absorbers on a self-passivating and insulating substrate. Nanoscale morphology and compositions of the photoanode after 600 h of testing were characterized to reveal the self-limiting corrosion behavior. It provides a promising approach to develop efficient but otherwise unstable absorbers such as III–V materials into defect-tolerant, corrosion-resistant photoanodes.


Item Type:Article
Related URLs:
URLURL TypeDescription
https://doi.org/10.1021/acsenergylett.0c02521DOIArticle
ORCID:
AuthorORCID
Sun, Ke0000-0001-8209-364X
Zhou, Chongwu0000-0001-8448-8450
Lewis, Nathan S.0000-0001-5245-0538
Hu, Shu0000-0002-5041-0169
Alternate Title:Defect-Tolerant TiO2-Coated and Discretized Photoanodes for >600 h of Stable Photoelectrochemical Water Oxidation
Additional Information:© 2020 American Chemical Society. Received: December 3, 2020; Accepted: December 9, 2020; Published: December 16, 2020. This work was supported through the Office of Science of the U.S. Department of Energy under Award No. DE-SC0004993 to the Joint Center for Artificial Photosynthesis, a DOE Energy Innovation Hub, and under Award Number DE-SC0001013 to the Center for Energy Nanoscience, an Energy Frontier Research Center (EFRC). We thank the Materials Characterization Core at Yale West Campus for SEM characterization. The authors declare no competing financial interest.
Group:JCAP
Funders:
Funding AgencyGrant Number
Department of Energy (DOE)DE-SC0004993
Department of Energy (DOE)DE-SC0001013
Subject Keywords:Photonics, Oxides, Absorption, Nanowires, Gallium arsenide
Issue or Number:1
Record Number:CaltechAUTHORS:20201217-143607686
Persistent URL:https://resolver.caltech.edu/CaltechAUTHORS:20201217-143607686
Official Citation:Defect-Tolerant TiO2-Coated and Discretized Photoanodes for >600 h of Stable Photoelectrochemical Water Oxidation. Xin Shen, Maoqing Yao, Ke Sun, Tianshuo Zhao, Yulian He, Chun-Yung Chi, Chongwu Zhou, Paul Daniel Dapkus, Nathan S. Lewis, and Shu Hu. ACS Energy Letters 2021 6 (1), 193-200; DOI: 10.1021/acsenergylett.0c02521
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:107175
Collection:CaltechAUTHORS
Deposited By: George Porter
Deposited On:18 Dec 2020 15:04
Last Modified:13 Jan 2021 22:55

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