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Communication
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remains on the WO3 surface after oxygen evolution, the Faradaic
efficiency of a 1-WO3 electrode was measured for 3 h, then the
electrolyte was discarded, fresh degassed electrolyte was
introduced into the cell, and oxygen evolution from the same
1-WO3 film was repeated for another 3 h. After this second
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One final point of note is that at pH 3, any iron species
removed from the electrode surface is soluble in water. ESI mass
spectrometry of the electrolyte following photoelectrolysis only
shows peaks corresponding to 1, including the hydrolysis of the
phosphonate esters, as mostly FeV or FeVI fragments (Figure
S17). A CV of the supporting electrolyte further supports high
valent iron dissociating during photoelectrolysis (Figure S18).
Although some of the complex dissociates from the surface, SEM
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WO3 after oxygen evolution (Figure S19). These data support
the notion that the catalyst is not decomposing to form Fe2O3
under illumination in the presence of oxidative holes from WO3.
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ASSOCIATED CONTENT
* Supporting Information
■
S
Experimental procedures, UV−vis and Raman spectra, cyclic
voltammograms, O2 evolution data, SEM images, and a CIF file.
This material is available free of charge via the Internet at http://
AUTHOR INFORMATION
Corresponding Author
■
Notes
(24) (a) Delroisse, M.; Rabion, A.; Chardac, F.; Tet
́
ard, D.; Verlhac, J.-
The authors declare no competing financial interest.
B.; Fraisse, L.; Seris, J.-L. J. Chem. Soc., Chem. Commun. 1995, 949.
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(b) Mialane, P.; Tchertanov, L.; Banse, F.; Sainton, J.; Girerd, J.-J. Inorg.
Chem. 2000, 39, 2440. (c) England, J.; Gondhia, R.; Bigorra-Lopez, L.;
Petersen, A. R.; White, A. J. P.; Britovsek, G. J. P. Dalton Trans. 2009,
5319.
(25) Coates, C. M.; Hagan, K.; Mitchell, C. A.; Gorden, J. D.;
Goldsmith, C. R. Dalton Trans. 2011, 40, 4048.
ACKNOWLEDGMENTS
■
This research was supported by a grant from the United States
Department of Energy (DE-FG02-11ER16262). We thank Dr.
Jeff W. Kampf for assistance with X-ray crystallography.
(26) Santato, C.; Odziemkowski, M.; Ulmann, M.; Augustynski, J. J.
Am. Chem. Soc. 2001, 123, 10639.
(27) Chen, G.; Chen, J.; Ng, S.-M.; Man, W.-L.; Lau, T.-C. Angew.
Chem., Int. Ed. 2013, 52, 1.
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