Electrochemical Deposition of Nanostructured Metal/Metal-Oxide Coatings
Electrochemical deposition finds applications in the electronics- and protective coating industries. The technique is a versatile tool for the synthesis of alloys and thin films. Knowledge of the fundamental aspects of the electrode processes enables the design of nanostructured materials. In this t...
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Uppsala universitet, Institutionen för materialkemi
2007
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ndltd-UPSALLA1-oai-DiVA.org-uu-81862013-01-08T13:07:15ZElectrochemical Deposition of Nanostructured Metal/Metal-Oxide CoatingsengEskhult, JonasUppsala universitet, Institutionen för materialkemiUppsala : Acta Universitatis Upsaliensis2007Inorganic chemistryelectrochemical depositionlocal pHCu2OSb2O3complexEQCMreductionOorganisk kemiElectrochemical deposition finds applications in the electronics- and protective coating industries. The technique is a versatile tool for the synthesis of alloys and thin films. Knowledge of the fundamental aspects of the electrode processes enables the design of nanostructured materials. In this thesis, electrodeposition processes in solutions containing metal ion complexes were studied and new methods for the preparation of metal/metal-oxide coatings were developed and evaluated. Metal/metal oxide coatings were electrodeposited from aqueous solutions containing metal complexes of hydroxycarboxylic acids under reducing conditions. The mass changes of the working electrode were monitored in-situ with the electrochemical quartz crystal microbalance (EQCM) technique and ellipsometry was used to detect the formation of Cu2O. The coatings were further characterized with XRD, XPS, SEM, TEM, and Raman spectroscopy. Electrochemical methods, including reduction of Sb/Sb2O3 in an organic electrolyte, were also used to study the properties of the deposited materials. Nanostructured coatings of Cu/Cu2O were obtained during spontaneous potential or current oscillations in alkaline Cu(II)-citrate solutions. The oscillations were due to local pH variations induced by a subsequent chemical step and comproportionation between Cu and Cu2+. Well-defined layers of Cu and Cu2O could be prepared by a galvanostatic pulsing technique, allowing independently controlled thickness of several hundred nanometers. Coatings, containing Sb and co-deposited, nanograins of Sb2O3, with a thickness of up to 200 nm were prepared from poorly buffered Sb(III)-tartrate solutions. Galvanostatic cycling showed that the latter material could be reversibly charged and discharged in a Li-ion battery for more than 50 cycles with a capacity of 660 mAh/g. The results show that precipitations of metal oxides can occur due to local pH increases during electrochemical deposition from metal complexes with ligands containing hydroxyl groups. The ability to deposit metal oxides using cathodic deposition relies on a sufficiently slow reduction of the oxide. Doctoral thesis, comprehensive summaryinfo:eu-repo/semantics/doctoralThesistexthttp://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-8186urn:isbn:978-91-554-6956-6Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, 1651-6214 ; 336application/pdfinfo:eu-repo/semantics/openAccess |
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English |
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Doctoral Thesis |
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Inorganic chemistry electrochemical deposition local pH Cu2O Sb2O3 complex EQCM reduction Oorganisk kemi |
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Inorganic chemistry electrochemical deposition local pH Cu2O Sb2O3 complex EQCM reduction Oorganisk kemi Eskhult, Jonas Electrochemical Deposition of Nanostructured Metal/Metal-Oxide Coatings |
description |
Electrochemical deposition finds applications in the electronics- and protective coating industries. The technique is a versatile tool for the synthesis of alloys and thin films. Knowledge of the fundamental aspects of the electrode processes enables the design of nanostructured materials. In this thesis, electrodeposition processes in solutions containing metal ion complexes were studied and new methods for the preparation of metal/metal-oxide coatings were developed and evaluated. Metal/metal oxide coatings were electrodeposited from aqueous solutions containing metal complexes of hydroxycarboxylic acids under reducing conditions. The mass changes of the working electrode were monitored in-situ with the electrochemical quartz crystal microbalance (EQCM) technique and ellipsometry was used to detect the formation of Cu2O. The coatings were further characterized with XRD, XPS, SEM, TEM, and Raman spectroscopy. Electrochemical methods, including reduction of Sb/Sb2O3 in an organic electrolyte, were also used to study the properties of the deposited materials. Nanostructured coatings of Cu/Cu2O were obtained during spontaneous potential or current oscillations in alkaline Cu(II)-citrate solutions. The oscillations were due to local pH variations induced by a subsequent chemical step and comproportionation between Cu and Cu2+. Well-defined layers of Cu and Cu2O could be prepared by a galvanostatic pulsing technique, allowing independently controlled thickness of several hundred nanometers. Coatings, containing Sb and co-deposited, nanograins of Sb2O3, with a thickness of up to 200 nm were prepared from poorly buffered Sb(III)-tartrate solutions. Galvanostatic cycling showed that the latter material could be reversibly charged and discharged in a Li-ion battery for more than 50 cycles with a capacity of 660 mAh/g. The results show that precipitations of metal oxides can occur due to local pH increases during electrochemical deposition from metal complexes with ligands containing hydroxyl groups. The ability to deposit metal oxides using cathodic deposition relies on a sufficiently slow reduction of the oxide. |
author |
Eskhult, Jonas |
author_facet |
Eskhult, Jonas |
author_sort |
Eskhult, Jonas |
title |
Electrochemical Deposition of Nanostructured Metal/Metal-Oxide Coatings |
title_short |
Electrochemical Deposition of Nanostructured Metal/Metal-Oxide Coatings |
title_full |
Electrochemical Deposition of Nanostructured Metal/Metal-Oxide Coatings |
title_fullStr |
Electrochemical Deposition of Nanostructured Metal/Metal-Oxide Coatings |
title_full_unstemmed |
Electrochemical Deposition of Nanostructured Metal/Metal-Oxide Coatings |
title_sort |
electrochemical deposition of nanostructured metal/metal-oxide coatings |
publisher |
Uppsala universitet, Institutionen för materialkemi |
publishDate |
2007 |
url |
http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-8186 http://nbn-resolving.de/urn:isbn:978-91-554-6956-6 |
work_keys_str_mv |
AT eskhultjonas electrochemicaldepositionofnanostructuredmetalmetaloxidecoatings |
_version_ |
1716509456738549760 |