Lu Fang, Zhang Yugang, Zhang Lihua, Su Dong, Zhuang Zechao, Liu Mingzhao, Chen Jingguang G, Gang Oleg
Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, New York 11973-5000, United States.
Department of Chemical Engineering, Columbia University, New York City, New York 10027, United States.
J Am Chem Soc. 2025 Jul 23;147(29):25871-25882. doi: 10.1021/jacs.5c08014. Epub 2025 Jul 14.
Shape control of nanocrystals (NCs) is crucial for tuning their assembly behavior and functional properties, yet the precise manipulation of facet composition remains challenging. Here, we present a nanocrystal reshaping strategy to control and modulate the facets of gold (Au) NCs. Our one-pot approach, conducted at room temperature, requires only initial Au NCs, Au ions, and surfactants, distinguishing it from conventional reduction-mediated "etching-and-regrowth" methods. Detailed structural studies using electron microscopy, small-angle X-ray scattering (SAXS), and UV-vis spectroscopy reveal the surfactant-encoded pathway for NC transformation from shaped particles to spheres and then into various polyhedral shapes while preserving the individual particles' volume. The proposed reshaping mechanism involves the dissolution of surface Au atoms into Au complexes in the presence of Au and surfactant, followed by surfactant-guided redeposition and formation of facets with different atomic planes. Using the ethanol oxidation reaction (EOR) as a probe, we observe a quasi-linear decrease in onset potential and an increase in activity with increasing {100} facet exposure. This work broadens synthetic strategies by offering precise NC reshaping and facet control.
纳米晶体（NCs）的形状控制对于调节其组装行为和功能特性至关重要，然而，精确控制晶面组成仍然具有挑战性。在此，我们提出了一种纳米晶体重塑策略，以控制和调节金（Au）纳米晶体的晶面。我们的一锅法在室温下进行，仅需初始的金纳米晶体、金离子和表面活性剂，这使其有别于传统的还原介导的“蚀刻-再生长”方法。使用电子显微镜、小角X射线散射（SAXS）和紫外-可见光谱进行的详细结构研究揭示了表面活性剂编码的纳米晶体从成型颗粒转变为球体，然后转变为各种多面体形状的途径，同时保留了单个颗粒的体积。所提出的重塑机制涉及在金和表面活性剂存在下，表面金原子溶解为金络合物，随后表面活性剂引导再沉积并形成具有不同原子平面的晶面。以乙醇氧化反应（EOR）为探针，我们观察到起始电位呈准线性下降，且随着{100}晶面暴露量的增加活性增强。这项工作通过提供精确的纳米晶体重塑和晶面控制拓宽了合成策略。
