D-Glucose-Derived Polymer Intermediates as Templates for the Synthesis of Ultrastable and Redispersible Gold Colloids
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- 作者：Ziyi Zhong ; Daohao Sim ; Jaclyn Teo ; Jizhong Luo ; Huajun Zhang ; Aharon Gedanken
- 刊名：Langmuir
- 出版年：2008
- 出版时间：May 6, 2008
- 年：2008
- 卷：24
- 期：9
- 页码：4655 - 4660
- 全文大小：436K
- 年卷期：v.24,no.9(May 6, 2008)
- ISSN：1520-5827
文摘
A two-stage hydrothermal process was developed for the synthesis of highly dispersed Au colloids. In the first stage,a novel glucose-derived polymer template was prepared by the hydrothermal treatment of glucose at 160 
C. Thistemplate was then further used in the next step to synthesize highly dispersed gold (Au) colloids by hydrothermaltreatment with HAuCl4. The templates treated at 160 C with changing reaction times had different templating effectstoward Au species. The 3-h treated template was able tightly adhere to the Au colloids. As a result, an unusual stabilitywas observed for the prepared Au particles that could be repeatedly precipitated and redispersed with the templatein H2O and were also stable against heating (below 160 C) and aging. Meanwhile, the 5-h and 7-h treated templateshad much poorer templating effects to Au species, leading to severe aggregation of the Au colloids immobilized onthem. The various templating effects were correlated to the different structural features of the templates. Comparedto the 5- or 7-h treated templates that were deeply carbonized, the 3-h treated template was only slightly carbonized,thus possessing a lot of functional and hydrophilic O-containing groups that could bind to Au species. These differencesin templating ability were also observed in the Au samples prepared by the sonication-assisted method. The highlydispersed Au colloids immobilized on the 3-h treated template were tested for CO oxidation, and a good catalyticactivity and stability for CO oxidation was observed.
C. Thistemplate was then further used in the next step to synthesize highly dispersed gold (Au) colloids by hydrothermaltreatment with HAuCl4. The templates treated at 160 C with changing reaction times had different templating effectstoward Au species. The 3-h treated template was able tightly adhere to the Au colloids. As a result, an unusual stabilitywas observed for the prepared Au particles that could be repeatedly precipitated and redispersed with the templatein H2O and were also stable against heating (below 160 C) and aging. Meanwhile, the 5-h and 7-h treated templateshad much poorer templating effects to Au species, leading to severe aggregation of the Au colloids immobilized onthem. The various templating effects were correlated to the different structural features of the templates. Comparedto the 5- or 7-h treated templates that were deeply carbonized, the 3-h treated template was only slightly carbonized,thus possessing a lot of functional and hydrophilic O-containing groups that could bind to Au species. These differencesin templating ability were also observed in the Au samples prepared by the sonication-assisted method. The highlydispersed Au colloids immobilized on the 3-h treated template were tested for CO oxidation, and a good catalyticactivity and stability for CO oxidation was observed.