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Tin Oxide as a Protective Heterojunction with Silicon for Efficient Photoelectrochemical Water Oxidation in Strongly Acidic or Alkaline Electrolytes

Moreno-Hernandez, Ivan A. and Brunschwig, Bruce S. and Lewis, Nathan S. (2018) Tin Oxide as a Protective Heterojunction with Silicon for Efficient Photoelectrochemical Water Oxidation in Strongly Acidic or Alkaline Electrolytes. Advanced Energy Materials, 8 (24). Art. No. 1801155. ISSN 1614-6832.

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Photoelectrodes without a p–n junction are often limited in efficiency by charge recombination at semiconductor surfaces and slow charge transfer to electrocatalysts. This study reports that tin oxide (SnO_x) layers applied to n‐Si wafers after forming a thin chemically oxidized SiO_x layer can passivate the Si surface while producing ≈620 mV photovoltage under 100 mW cm^(−2) of simulated sunlight. The SnO_x layer makes ohmic contacts to Ni, Ir, or Pt films that act as precatalysts for the oxygen‐evolution reaction (OER) in 1.0 m KOH(aq) or 1.0 m H_2SO_4(aq). Ideal regenerative solar‐to‐O_2(g) efficiencies of 4.1% and 3.7%, respectively, are obtained in 1.0 m KOH(aq) with Ni or in 1.0 m H2_SO_4(aq) with Pt/IrO_x layers as OER catalysts. Stable photocurrents for >100 h are obtained for electrodes with patterned catalyst layers in both 1.0 m KOH(aq) and 1.0 m H_2SO_4(aq).

Item Type:Article
Related URLs:
URLURL TypeDescription
Moreno-Hernandez, Ivan A.0000-0001-6461-9214
Brunschwig, Bruce S.0000-0002-6135-6727
Lewis, Nathan S.0000-0001-5245-0538
Additional Information:© 2018 WILEY‐VCH. Received: April 16, 2018. Revised: May 26, 2018. Version of Record online: 01 July 2018. This work was supported through the Office of Science of the U.S. Department of Energy (DOE) under award no. DE‐SC0004993 to the Joint Center for Artificial Photosynthesis, a DOE Energy Innovation Hub. I.A.M.‐H. acknowledges a National Science Foundation Graduate Research Fellowship under Grant No. DGE‐1144469. The authors thank C. Garland for assistance with transmission‐electron microscopy. The authors declare no conflict of interest.
Funding AgencyGrant Number
Department of Energy (DOE)DE-SC0004993
NSF Graduate Research FellowshipDGE‐1144469
Issue or Number:24
Record Number:CaltechAUTHORS:20180709-131016014
Persistent URL:
Official Citation:I. A. Moreno‐Hernandez, B. S. Brunschwig, N. S. Lewis, Adv. Energy Mater. 2018, 8, 1801155.
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:87651
Deposited By: George Porter
Deposited On:09 Jul 2018 20:31
Last Modified:03 Oct 2019 19:58

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