| 报告题目 | Controlled Synthesis of Noble Metal Nanoparticles and Their Applications |
| 报告人 | Prof. LU Xianmao |
| 报告人单位 | Department of Chemical & Biomolecular Engineering, National University of Singapore (NUS) |
| 报告时间 | 2014-10-29 |
| 报告地点 | 中国科学技术大学环境资源楼一楼学术报告厅 |
| 主办单位 | 合肥微尺度物质科学国家实验室、中国科学技术大学化学与材料科学学院 |
| 报告介绍 | 报告摘要：
Shape-selective synthesis of noble metal nanocrystals has attracted much attention in recent years owing to their shape-dependent properties and wide variety of applications. Among various approaches to tune the geometry of metal nanocrystals, the introduction of foreign ions in solution-phase syntheses has shown drastic morphology-selection effect. This strategy has been most successfully demonstrated in the gold-silver system where the presence of Ag(I) in trace amount induces the formation of Au nanocrystals with various shapes. Here, we present our recent study on using foreign ions (e.g., Pd2+, Ag+, Cu2+, and H+) as shape-selective agents for noble metal nanostructures with exotic shapes. In the first example, we show that by using a facile one-pot polyol process with the assistance of Pd2+/Ag+ ions, Au polyhedra with high-index facets including ditetragonal prisms enclosed by {310} facets, truncated octahedra with both {111} and {310} facets, and bipyramids bounded by {117} facets can be prepared in high yields. The underpotential deposition of the foreign metal ions should be accountable for the formation of the high-index facets. In another example, we found that Cu2+ can be used to tailor the shape of Pd nanocubes – by introducing different amount of Cu2+ ions in the synthesis, Pd concave nanocubes with sharp edges can be synthesized, although a mechanism different from previous case is governing the formation of the concave Pd nanocubes. In addition, we also show that novel bimetallic Pt-Ag nanostructures, including dimeric and popcorn-shaped hollow particles, can be synthesized via modified galvanic replacement reactions (GRRs) between Ag nanotemplates and Pt precursor. It’s found that by simply adding HCl to the reaction, the reaction kinetics and hence the number of pitting sites can be controlled to tune the diffusion of Ag and the deposition of Pt on Ag nanotemplates, leading to the formation of nanoboxes attached with different number of hollow particles. 个人简介： Xianmao Lu is an assistant professor in the Department of Chemical & Biomolecular Engineering at National University of Singapore (NUS). Before he joined NUS, he was a postdoctoral research fellow at University of Washington and Washington University. He received his PhD in Chemical Engineering from the University of Texas at Austin, where he started his research in nanomaterials. His current research interest is mainly on shape-selective growth of noble metal nanocrystals and understanding of their fundamental properties. |
