Uptake of Au(III) Ions by Aluminum Hydroxide and Their Spontaneous Reduction to Elemental Gold (Au(0))
✍ Scribed by Takushi Yokoyama; Yoko Matsukado; Akiko Uchida; Yoshinobu Motomura; Koichiro Watanabe; Eiji Izawa
- Publisher
- Elsevier Science
- Year
- 2001
- Tongue
- English
- Weight
- 173 KB
- Volume
- 233
- Category
- Article
- ISSN
- 0021-9797
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✦ Synopsis
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.