Dye-sensitized photoelectrochemical water oxidation through a buried junction

Pengtao Xu, Tian Huang, Jianbin Huang, Yun Yan, Thomas E. Mallouk

Research output: Contribution to journalArticle

8 Citations (Scopus)

Abstract

Water oxidation has long been a challenge in artificial photosynthetic devices that convert solar energy into fuels. Water-splitting dye-sensitized photoelectrochemical cells (WS-DSPECs) provide a modular approach for integrating light-harvesting molecules with water-oxidation catalysts on metal-oxide electrodes. Despite recent progress in improving the efficiency of these devices by introducing good molecular water-oxidation catalysts, WS-DSPECs have poor stability, owing to the oxidation of molecular components at very positive electrode potentials. Here we demonstrate that a solid-state dye-sensitized solar cell (ss-DSSC) can be used as a buried junction for stable photoelectrochemical water splitting. A thin protecting layer of TiO2 grown by atomic layer deposition (ALD) stabilizes the operation of the photoanode in aqueous solution, although as a solar cell there is a performance loss due to increased series resistance after the coating. With an electrodeposited iridium oxide layer, a photocurrent density of 1.43 mA cm2 was observed in 0.1 M pH 6.7 phosphate solution at 1.23 V versus reversible hydrogen electrode, with good stability over 1 h. We measured an incident photon-to-current efficiency of 22% at 540 nm and a Faradaic efficiency of 43% for oxygen evolution. While the potential profile of the catalyst layer suggested otherwise, we confirmed the formation of a buried junction in the as-prepared photoelectrode. The buried junction design of ss-DSSs adds to our understanding of semiconductor–electrocatalyst junction behaviors in the presence of a poor semiconducting material.

Original languageEnglish (US)
Pages (from-to)6946-6951
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America
Volume115
Issue number27
DOIs
StatePublished - Jul 3 2018

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Coloring Agents
Water
Electrodes
Solar Energy
Equipment and Supplies
Photons
Oxides
Hydrogen
Metals
Phosphates
Oxygen
Light

All Science Journal Classification (ASJC) codes

  • General

Cite this

Xu, Pengtao ; Huang, Tian ; Huang, Jianbin ; Yan, Yun ; Mallouk, Thomas E. / Dye-sensitized photoelectrochemical water oxidation through a buried junction. In: Proceedings of the National Academy of Sciences of the United States of America. 2018 ; Vol. 115, No. 27. pp. 6946-6951.
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Dye-sensitized photoelectrochemical water oxidation through a buried junction. / Xu, Pengtao; Huang, Tian; Huang, Jianbin; Yan, Yun; Mallouk, Thomas E.

In: Proceedings of the National Academy of Sciences of the United States of America, Vol. 115, No. 27, 03.07.2018, p. 6946-6951.

Research output: Contribution to journalArticle

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T1 - Dye-sensitized photoelectrochemical water oxidation through a buried junction

AU - Xu, Pengtao

AU - Huang, Tian

AU - Huang, Jianbin

AU - Yan, Yun

AU - Mallouk, Thomas E.

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