Uptake of Au(III) Ions by Aluminum Hydroxide and Their Spontaneous Reduction to Elemental Gold (Au(0)).
The behavior of AuCl(4)(-) ions during the formation of aluminum hydroxide at pH 6 was examined. With an increase in NaCl concentration, the content of gold taken up by aluminum hydroxide decreased, suggesting that chloro-hydroxy complexes of Au(III) ion were taken up due to the formation of Al-O-Au bonds. It was found unexpectedly that the Au(III) ions taken up were spontaneously reduced to elemental gold without addition of a specific reducing reagent and then colloidal gold particles were formed. The mechanisms for the uptake of Au(III) ions by aluminum hydroxide and for their spontaneous reduction are discussed. Copyright 2001 Academic Press.
Yokoyama
T
Department of Chemistry, Faculty of Science, Kyushu University, Hakozaki, Higashi-ku, Fukuoka, 812-8581, Japan
Matsukado
Y
Uchida
A
Motomura
Y
Watanabe
K
Izawa
E