Hongpo’s work on the etching-free epitaxial growth of Au on Ag nanostructures for high chemical stability and plasmonic activities has been accepted by the Advanced Functional Materials (impact factor: 11.8). This work has been selected as back cover of the issue. Congratulations!

Title: Etching-free epitaxial growth of gold on silver nanostructures for high chemical stability and plasmonic activity

Authors: Hongpo Liu, Tingzhuo Liu, Lei Zhang, Lu Han, Chuanbo Gao,* and Yadong Yin*

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Abstract: A robust method for epitaxial deposition of Au onto the surface of Ag nanostructures is demonstrated, which allows effective conversion of Ag nano­structures of various morphologies into Ag@Au counterparts, with the anisotropic ones showing excellent plasmonic properties comparable to the original Ag nanostructures while significantly enhanced stability. Sulfite plays a determining role in the success of this epitaxial deposition as it strongly complexes with gold cations to completely prevent galvanic replacement while it also remains benign to the Ag surface to avoid any ligand-assisted oxidative etching. By using Ag nanoplates as an example, it is shown that the corresponding Ag@Au nanoplates possess remarkable plasmonic properties that are virtually Ag-like, in clear contrast to Ag@Au nanospheres that exhibit much lower plasmonic activities than their Ag counterparts. As a result, they display high durability and activities in surface-enhanced Raman scattering applications. This strategy may represent a general platform for depositing a noble metal on less stable metal nanostructures, thus opening up new opportunities in rational design of functional metal nanomaterials for a broad range of applications.

中文简介：具有规整形貌的金纳米晶的可控制备是纳米材料合成领域的一项重要挑战。而银纳米晶由于具有形貌的多样性和制备的可控性，以其为模板实现金的外延生长可成为制备金纳米晶的替代方案。由于置换反应的发生，通常只能得到具有空心结构的纳米材料。本工作以银纳米片为例，通过引入配位作用抑制了置换反应的发生，实现了金在银表面上的外延生长，最终形成了一种新颖的具有核壳结构的“准金”纳米片材料。该材料表现出优异的稳定性和光学活性，在分子检测、生物传感与成像等领域具有良好的应用前景。该合成策略为活泼金属表面沉积贵金属提供了通用的方法，为功能贵金属纳米材料的设计合成、活泼金属抗腐蚀保护层的制备等方向提供了新的思路。

该研究是在国家自然科学基金的支持下完成的，论文发表在材料领域权威期刊Advanced Functional Materials（影响因子：11.382）上，并被选为后封面。