Reduction and Accumulation of Gold(III) by Medicago sativa Alfalfa Biomass: X-ray Absorption Spectroscopy, pH, and Temperature Dependence.
Reduction and Accumulation of Gold(III) by Medicago sativa Alfalfa Biomass: X-ray Absorption Spectroscopy, pH, and Temperature Dependence.
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DOI：
10.1021/es991325m
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发表时间：
2000-10
影响因子：
11.4
通讯作者：
J. Gardea-Torresdey;K. Tiemann;G. Gamez;K. Dokken;I. Cano‐Aguilera;L. Furenlid;M. Renner
中科院分区：
文献类型：
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作者：
J. Gardea-Torresdey;K. Tiemann;G. Gamez;K. Dokken;I. Cano‐Aguilera;L. Furenlid;M. Renner
我们在此报告了使用苜蓿苜蓿芽生物质从水溶液中去除金。积累过程涉及 Au(III) 还原为胶体 Au(0)，并且在升高的温度和较低的 pH 值下会增加。 X 射线吸收光谱 (XAS) 用于确定金 (III) 被还原形成金 (0) 胶体，其大小根据初始溶液的 pH 值而变化。金簇半径在 pH 5 时为 6.2 ± 1 Å，在 pH 2 时为 9.0 ± 1 Å。我们的研究结果表明，在 pH 2 时，实质上另一层金原子沉积在胶体表面上。讨论了生物还原和积累的可能机制。
We report herein the use of Medicago sativa alfalfa shoot biomass for the removal of gold from aqueous solutions. The accumulation process involves the reduction of Au(III) to colloidal Au(0) and is shown to increase at elevated temperatures and at lower pH. X-ray absorption spectroscopy (XAS) was used to determine that gold(III) was reduced to form gold(0) colloids, which varied in size depending on the pH of the initial solution. The gold cluster radius was 6.2 ± 1 Å at pH 5 and 9.0 ± 1 Å at pH 2. Our findings indicate that essentially another layer of gold atoms was deposited onto the colloid surface at pH 2. Possible mechanisms of bioreduction and accumulation are discussed.