Reductive deposition of Au3+(aq) on oxidized silicon surfaces
Author
Süzer, Ş.
Dag, Ö.
Date
2000Source Title
Canadian Journal of Chemistry
Print ISSN
0008-4042
Publisher
N R C Research Press
Volume
78
Issue
4
Pages
516 - 519
Language
English
Type
ArticleItem Usage Stats
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Abstract
X-ray photoelectron spectroscopy (XPS) is used to determine the oxidation state of gold deposited from an aqueous solution of AuCl4- on to various oxidized surfaces of silicon. Although the observed Au4f signal decreased with the thickness of the oxide layer, the oxidation state of Au was determined as 0 for all the samples analyzed. From the angular dependence of the Si2p and Au4f signals it was determined that Au is deposited on top of the oxidized surfaces of metallic silicon. It is postulated that from an aqueous solution of AuCl4-, gold would deposit in its zerovalent form on to any surface due to its large and positive electrochemical reduction potential (ε° (red) (Au3+/Au) = +1.50 V) and the substrate plays a role only in providing active deposition sites. To further support the proposal, it is shown that the same process takes place even in inert and hydrophobic polypropylene substrates. Similarly, it is also shown that more gold deposits if the surface of the polypropylene is made less hydrophobic (but probably more active) via the industrially used corona discharge treatment.
Keywords
Electroless depositionGold
Oxidized silicon surface
XPS
Electrochemistry
Hydrophobicity
Oxidation reduction reaction
X ray spectrometry