CaltechAUTHORS
  A Caltech Library Service

In situ probe of photocarrier dynamics in water-splitting hematite (α-Fe_(2)O_3) electrodes

Huang, Zhuangqun and Lin, Yongjing and Xiang, Xu and Rodríguez-Córdoba , William and McDonald, Kenneth J. and Hagen, Karl S. and Choi, Kyoung-Shin and Brunschwig, Bruce S. and Musaev, Djamaladdin G. and Hill, Craig L. and Wang, Dunwei and Lian, Tianquan (2012) In situ probe of photocarrier dynamics in water-splitting hematite (α-Fe_(2)O_3) electrodes. Energy and Environmental Science, 5 (10). pp. 8923-8926. ISSN 1754-5692. https://resolver.caltech.edu/CaltechAUTHORS:20121025-155412662

[img]
Preview
PDF - Published Version
See Usage Policy.

210Kb
[img]
Preview
PDF - Supplemental Material
See Usage Policy.

1113Kb

Use this Persistent URL to link to this item: https://resolver.caltech.edu/CaltechAUTHORS:20121025-155412662

Abstract

The spectra and dynamics of photogenerated electrons and holes in excited hematite (α-Fe_(2)O_3) electrodes are investigated by transient absorption (from visible to infrared and from femto- to micro-seconds), bias-dependent differential absorption and Stark spectroscopy. Comparison of results from these techniques enables the assignment of the spectral signatures of photogenerated electrons and holes. Under the pulse illumination conditions of transient absorption (TA) measurement, the absorbed photon to electron conversion efficiency (APCE) of the films at 1.43 V (vs. reversible hydrogen electrode, RHE) is 0.69%, significantly lower than that at AM 1.5. TA kinetics shows that under these conditions, >98% of the photogenerated electrons and holes have recombined by 6 μs. Although APCE increases with more positive bias (from 0.90 to 1.43 V vs. RHE), the kinetics of holes up to 6 μs show negligible change, suggesting that the catalytic activity of the films is determined by holes with longer lifetimes.


Item Type:Article
Related URLs:
URLURL TypeDescription
http://dx.doi.org/10.1039/c2ee22681bDOIArticle
http://pubs.rsc.org/en/Content/ArticleLanding/2012/EE/c2ee22681bPublisherArticle
ORCID:
AuthorORCID
Brunschwig, Bruce S.0000-0002-6135-6727
Additional Information:© 2012 Royal Society of Chemistry. Received 27th June 2012, Accepted 9th August 2012. First published on the web 09 Aug 2012. DGM, CLH and TL acknowledge the support of the U.S. Department of Energy, Office of Basic Energy Sciences, Solar Photochemistry Program (DE-FG02-07ER-15906); financial support for BSB was provided by an NSF Center for Chemical Innovation (CHE-0802907) at Caltech. YJ and DW are supported by NSF through a CAREER Award (DMR-1055762). KJM and KSC acknowledge the support by the U.S. Department of Energy, Office of BasicEnergy Sciences, Solar Photochemistry Program (DE-FG02-05ER15752); steady-state Stark spectral data were collected at the Molecular Materials Research Center of the Beckman Institute of the California Institute of Technology. ZH is grateful to the productive discussion with the members of Lewis group.
Group:CCI Solar Fuels
Funders:
Funding AgencyGrant Number
Department of Energy (DOE)DE-FG02-07ER-15906
NSFCHE-0802907
NSFDMR-1055762
Department of Energy (DOE)DE-FG02-05ER15752
Issue or Number:10
Record Number:CaltechAUTHORS:20121025-155412662
Persistent URL:https://resolver.caltech.edu/CaltechAUTHORS:20121025-155412662
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:35105
Collection:CaltechAUTHORS
Deposited By: Jason Perez
Deposited On:26 Oct 2012 18:29
Last Modified:03 Oct 2019 04:25

Repository Staff Only: item control page