Energetics and kinetics of light-driven oxygen evolution at semiconductor electrodes: the example of hematite

Research output: Contribution to journalArticle

  • 101 Citations

Abstract

Light-driven water-splitting (photoelectrolysis) at semiconductor electrodes continues to excite interest as a potential route to produce hydrogen as a sustainable fuel, but surprisingly little is known about the kinetics and mechanisms of the reactions involved. Here, some basic principles of semiconductor photoelectrochemistry are reviewed with particular emphasis on the effects of slow interfacial electron transfer at n-type semiconductors in the case of light-driven oxygen evolution. A simple kinetic model is outlined that considers the competition between interfacial transfer of photogenerated holes and surface recombination. The model shows that, if interfacial charge transfer is very slow, the build-up of holes at the surface will lead to substantial changes in the potential drop across the Helmholtz layer, leading to non-ideal behavior (Fermi level pinning). The kinetic model is also used to predict the response of photoanodes to chopped illumination and to periodic perturbations of illumination and potential. Recent experimental results obtained for α-Fe 2O 3 (hematite) photoanodes are reviewed and interpreted within the framework of the model.
LanguageEnglish
Pages315-326
JournalJournal of Solid State Electrochemistry
Volume17
Issue number2
DOIs
StatusPublished - Feb 2013

Fingerprint

Hematite
hematite
Semiconductor materials
Oxygen
Electrodes
Kinetics
electrodes
kinetics
oxygen
Lighting
illumination
photoelectrochemistry
n-type semiconductors
water splitting
Fermi level
Charge transfer
Hydrogen
electron transfer
routes
charge transfer

Cite this

@article{514148b3d14b49798a2a50b74fc69a9e,
title = "Energetics and kinetics of light-driven oxygen evolution at semiconductor electrodes: the example of hematite",
abstract = "Light-driven water-splitting (photoelectrolysis) at semiconductor electrodes continues to excite interest as a potential route to produce hydrogen as a sustainable fuel, but surprisingly little is known about the kinetics and mechanisms of the reactions involved. Here, some basic principles of semiconductor photoelectrochemistry are reviewed with particular emphasis on the effects of slow interfacial electron transfer at n-type semiconductors in the case of light-driven oxygen evolution. A simple kinetic model is outlined that considers the competition between interfacial transfer of photogenerated holes and surface recombination. The model shows that, if interfacial charge transfer is very slow, the build-up of holes at the surface will lead to substantial changes in the potential drop across the Helmholtz layer, leading to non-ideal behavior (Fermi level pinning). The kinetic model is also used to predict the response of photoanodes to chopped illumination and to periodic perturbations of illumination and potential. Recent experimental results obtained for α-Fe 2O 3 (hematite) photoanodes are reviewed and interpreted within the framework of the model.",
author = "L.M. Peter",
year = "2013",
month = "2",
doi = "10.1007/s10008-012-1957-3",
language = "English",
volume = "17",
pages = "315--326",
journal = "Journal of Solid State Electrochemistry",
issn = "1432-8488",
publisher = "Springer Verlag",
number = "2",

}

TY - JOUR

T1 - Energetics and kinetics of light-driven oxygen evolution at semiconductor electrodes

T2 - Journal of Solid State Electrochemistry

AU - Peter, L.M.

PY - 2013/2

Y1 - 2013/2

N2 - Light-driven water-splitting (photoelectrolysis) at semiconductor electrodes continues to excite interest as a potential route to produce hydrogen as a sustainable fuel, but surprisingly little is known about the kinetics and mechanisms of the reactions involved. Here, some basic principles of semiconductor photoelectrochemistry are reviewed with particular emphasis on the effects of slow interfacial electron transfer at n-type semiconductors in the case of light-driven oxygen evolution. A simple kinetic model is outlined that considers the competition between interfacial transfer of photogenerated holes and surface recombination. The model shows that, if interfacial charge transfer is very slow, the build-up of holes at the surface will lead to substantial changes in the potential drop across the Helmholtz layer, leading to non-ideal behavior (Fermi level pinning). The kinetic model is also used to predict the response of photoanodes to chopped illumination and to periodic perturbations of illumination and potential. Recent experimental results obtained for α-Fe 2O 3 (hematite) photoanodes are reviewed and interpreted within the framework of the model.

AB - Light-driven water-splitting (photoelectrolysis) at semiconductor electrodes continues to excite interest as a potential route to produce hydrogen as a sustainable fuel, but surprisingly little is known about the kinetics and mechanisms of the reactions involved. Here, some basic principles of semiconductor photoelectrochemistry are reviewed with particular emphasis on the effects of slow interfacial electron transfer at n-type semiconductors in the case of light-driven oxygen evolution. A simple kinetic model is outlined that considers the competition between interfacial transfer of photogenerated holes and surface recombination. The model shows that, if interfacial charge transfer is very slow, the build-up of holes at the surface will lead to substantial changes in the potential drop across the Helmholtz layer, leading to non-ideal behavior (Fermi level pinning). The kinetic model is also used to predict the response of photoanodes to chopped illumination and to periodic perturbations of illumination and potential. Recent experimental results obtained for α-Fe 2O 3 (hematite) photoanodes are reviewed and interpreted within the framework of the model.

UR - http://www.scopus.com/inward/record.url?scp=84869872745&partnerID=8YFLogxK

UR - http://dx.doi.org/10.1007/s10008-012-1957-3

U2 - 10.1007/s10008-012-1957-3

DO - 10.1007/s10008-012-1957-3

M3 - Article

VL - 17

SP - 315

EP - 326

JO - Journal of Solid State Electrochemistry

JF - Journal of Solid State Electrochemistry

SN - 1432-8488

IS - 2

ER -