美国加州大学Yadong Yin团体报道了具有表面凹度的热致变色金纳米棒的生成与重建。相关研究成果于2021年9月14日发表于国际一流学术期刊《美国化学会杂志》。

由于热力学偏好，传统的胶体合成通常产生具有正曲率的纳米结构。

该文中，研究人员展示了在密闭空间通过种子介导在金纳米棒中产生表面凹度，并报告了它们对温度变化的热致变色反应。独特的表面凹度是通过模板作用在Fe₃O₄纳米棒上形成的，产生了一个新的凹度敏感等离子体带。由于具有较高的表面能，亚稳纳米棒可以在中等温度下重建，通过在不同溶剂中老化，可以方便而精确地调节其等离子体特性。该凹形金纳米棒的结构重建使得热致变色等离子体薄膜的制造成为可能，该薄膜可以显示具有生动颜色变化的图像，或者在老化时显示加密的、不可见的信息。

该模板化策略在创建凹面纳米结构方面是通用的，可能为设计新的纳米结构打开大门，在传感、防伪、信息加密和显示方面具有广阔的应用前景。

附：英文原文

Title: Creation and Reconstruction of Thermochromic Au Nanorods with Surface Concavity

Author: Zhiwei Li, Jian Zhang, Jianbo Jin, Fan Yang, Rashed Aleisa, Yadong Yin

Issue&Volume: September 14, 2021

Abstract: Conventional colloidal syntheses typically produce nanostructures with positive curvatures due to thermodynamic preference. Here, we demonstrate the creation of surface concavity in Au nanorods through seed-mediated growth in confined spaces and report their thermochromic responses to temperature changes. The unique surface concavity is created by templating against Fe3O4 nanorods, producing a new concavity-sensitive plasmonic band. Due to the high surface energy, the metastable nanorods can be reconstructed at a moderate temperature, enabling convenient and precise tuning of their plasmonic properties by aging in different solvents. Such structural reconstruction of concave Au nanorods enables the fabrication of thermochromic plasmonic films that can display images with vivid color changes or exhibit encrypted, invisible information upon aging. This templating strategy is universal in creating concave nanostructures, which may open the door to designing new nanostructures with promising applications in sensing, anticounterfeiting, information encryption, and displays.

DOI: 10.1021/jacs.1c07241

Source: https://pubs.acs.org/doi/10.1021/jacs.1c07241