Department of Chemistry, Indiana University, 800 East Kirkwood Avenue, Bloomington, Indiana 47405, United States.
Nano Lett. 2020 Oct 14;20(10):7263-7271. doi: 10.1021/acs.nanolett.0c02648. Epub 2020 Sep 11.
We report a heterometallic seed-mediated synthesis method for monodisperse penta-twinned Cu nanorods using Au nanocrystals as seeds. Elemental analyses indicate that resultant nanorods consist predominantly of copper with a gold content typically below 3 atom %. The nanorod aspect ratio can be readily adjusted from 2.8 to 13.1 by varying the molar ratio between Au seeds and Cu precursor, resulting in narrow longitudinal plasmon resonances tunable from 762 to 2201 nm. Studies of reaction intermediates reveal that symmetry-breaking is promoted by rapid nanoscale diffusion in Au-Cu alloys and the formation of a gold-rich surface. The growth pathway features coevolving shape and composition whereby nanocrystals become progressively enriched with Cu concomitant with nanorod growth. The availability of uniform colloidal Cu nanorods with widely tunable aspect ratios opens new avenues toward the synthesis of derivative one-dimensional metal nanostructures, and applications in surface-enhanced spectroscopy, bioimaging, and electrocatalysis, among others.
我们报告了一种使用金纳米晶作为种子的异金属种子介导的单分散五孪晶 Cu 纳米棒的合成方法。元素分析表明，所得纳米棒主要由铜组成，金含量通常低于 3 原子%。通过改变 Au 种子和 Cu 前体之间的摩尔比，很容易将纳米棒的纵横比从 2.8 调整到 13.1，从而实现从 762 到 2201nm 的可调谐纵向等离子体共振。对反应中间体的研究表明，对称破缺是由 Au-Cu 合金中的快速纳米尺度扩散和富金表面的形成所促进的。生长途径的特点是形状和组成的共同演变，纳米晶随着纳米棒的生长而逐渐富集 Cu。均匀胶体 Cu 纳米棒的可用性，其纵横比具有广泛的可调性，为合成衍生的一维金属纳米结构开辟了新途径，并在表面增强光谱学、生物成像和电催化等领域有应用。
