Redox-active monolayers in mesoporous silicon

Herein, redox reactions at chemically derivatized porous silicon (PSi) films are investigated. Passivation of the PSi matrix, by replacing metastable Si-H termini with nonpolar Si-C=C-R linkages, allows the electrochemical PSi device to operate in aqueous environments under oxidizing conditions (i.e...

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Main Authors: Ciampi, S., Guan, B., Darwish, Nadim, Reece, P., Gooding, J.
Format: Journal Article
Published: American Chemical Society 2012
Online Access:http://hdl.handle.net/20.500.11937/39356
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author Ciampi, S.
Guan, B.
Darwish, Nadim
Reece, P.
Gooding, J.
author_facet Ciampi, S.
Guan, B.
Darwish, Nadim
Reece, P.
Gooding, J.
author_sort Ciampi, S.
building Curtin Institutional Repository
collection Online Access
description Herein, redox reactions at chemically derivatized porous silicon (PSi) films are investigated. Passivation of the PSi matrix, by replacing metastable Si-H termini with nonpolar Si-C=C-R linkages, allows the electrochemical PSi device to operate in aqueous environments under oxidizing conditions (i.e., electron hole accumulation regime). Cu(I)-catalyzed alkyne-azide cycloaddition reactions are used to anchor ferrocene derivatives and probe electrochemical reactions at the exceedingly large surface area-to-volume ratio of mesoporous PSi. The forward-biased p-type PSi/electrolyte interface retains a quasi-metallic behavior throughout its entire contour, and it does so for prolonged times even when the electrode is poised at potentials at which a bare silicon electrode would rapidly oxidize. The interfacial capacitance of the PSi matrix is, however, unexpectedly low. An explanation is proposed where PSi morphology and the semiconductor space-charge layer capacitance play a significant role in determining the charging properties of the electrode. These results are important for the application of porous semiconductor electrodes in sensing, electrocatalytic, and energy-conversion devices.
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publishDate 2012
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spelling curtin-20.500.11937-393562017-09-13T14:26:49Z Redox-active monolayers in mesoporous silicon Ciampi, S. Guan, B. Darwish, Nadim Reece, P. Gooding, J. Herein, redox reactions at chemically derivatized porous silicon (PSi) films are investigated. Passivation of the PSi matrix, by replacing metastable Si-H termini with nonpolar Si-C=C-R linkages, allows the electrochemical PSi device to operate in aqueous environments under oxidizing conditions (i.e., electron hole accumulation regime). Cu(I)-catalyzed alkyne-azide cycloaddition reactions are used to anchor ferrocene derivatives and probe electrochemical reactions at the exceedingly large surface area-to-volume ratio of mesoporous PSi. The forward-biased p-type PSi/electrolyte interface retains a quasi-metallic behavior throughout its entire contour, and it does so for prolonged times even when the electrode is poised at potentials at which a bare silicon electrode would rapidly oxidize. The interfacial capacitance of the PSi matrix is, however, unexpectedly low. An explanation is proposed where PSi morphology and the semiconductor space-charge layer capacitance play a significant role in determining the charging properties of the electrode. These results are important for the application of porous semiconductor electrodes in sensing, electrocatalytic, and energy-conversion devices. 2012 Journal Article http://hdl.handle.net/20.500.11937/39356 10.1021/jp303980x American Chemical Society restricted
spellingShingle Ciampi, S.
Guan, B.
Darwish, Nadim
Reece, P.
Gooding, J.
Redox-active monolayers in mesoporous silicon
title Redox-active monolayers in mesoporous silicon
title_full Redox-active monolayers in mesoporous silicon
title_fullStr Redox-active monolayers in mesoporous silicon
title_full_unstemmed Redox-active monolayers in mesoporous silicon
title_short Redox-active monolayers in mesoporous silicon
title_sort redox-active monolayers in mesoporous silicon
url http://hdl.handle.net/20.500.11937/39356