Nanocrystal cation exchange is a post-synthetic process that modifies the composition of a nanoparticle while maintaining other important characteristics, including morphology and crystal structure. Partial cation exchange reactions can be used to rationally synthesize heterostructured nanoparticles that contain two or more material segments. Increasingly complex heterostructured nanoparticles are accessible using multiple sequential cation exchange reactions, but achieving targeted structures in high yield requires careful consideration of synthetic parameters and chemical reactivity. Here, we discuss in detail the synthetic protocols used in two distinct partial cation exchange pathways that are differentiated based on the relative amounts of metal salt reagents—excess vs stoichiometric—that are used during the reaction. Using a model system obtained through Zn²⁺ exchange on roxbyite copper sulfide nanorods, we demonstrate how targeted products can be synthesized reproducibly. We show how small deviations in reaction conditions, such as temperature, time, and particle concentration, can significantly impact the outcome of these reactions. We highlight important chemical and physical hazards, issues that can be encountered when characterizing heterostructured nanoparticles, and troubleshooting suggestions for overcoming commonly encountered pitfalls. Clear and detailed descriptions of these aspects of partial cation exchange reactions are important for enabling widespread reproducibly and further development of the field.

中文翻译：

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部分阳离子交换反应合成异质结构金属硫化物纳米晶体的实验见解。

纳米晶体阳离子交换是一种后合成过程，可在保持其他重要特征（包括形态和晶体结构）的同时修饰纳米颗粒的组成。部分阳离子交换反应可用于合理合成包含两个或多个材料链段的异质结构纳米颗粒。可以使用多个顺序的阳离子交换反应来获得越来越复杂的异质结构纳米颗粒，但是要以高收率获得目标结构，则需要仔细考虑合成参数和化学反应性。在这里，我们详细讨论了在两个不同的部分阳离子交换途径中使用的合成方案，该方案基于反应期间使用的金属盐试剂的相对量（过量与化学计量）而有所区别。在roxbyite硫化铜纳米棒上进行²⁺交换，我们演示了如何可重复合成目标产物。我们展示了反应条件（例如温度，时间和颗粒浓度）的微小偏差如何对这些反应的结果产生重大影响。我们重点介绍了重要的化学和物理危害，表征异质结构纳米颗粒时可能遇到的问题以及解决常见缺陷的故障排除建议。对部分阳离子交换反应的这些方面的清楚而详细的描述对于实现广泛的可再现性和本领域的进一步发展是重要的。