Conversion of InP Clusters to Quantum Dots
Conversion of InP Clusters to Quantum Dots
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DOI：
10.1021/acs.inorgchem.8b02945
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发表时间：
2019-01-07
影响因子：
4.6
通讯作者：
Cossairt, Brandi M.
中科院分区：
文献类型：
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作者：
Friedfeld, Max R.;Johnson, Dane A.;Cossairt, Brandi M.
了解纳米材料合成过程中涉及的不同机制是制造具有理想功能的均匀材料所必需的。本研究利用原位光谱方法研究了磷化铟团簇表面的交换反应，发现团簇表面在室温下的核磁共振时间尺度上缺乏明显的动力学。在温度升高和羧酸和羧酸铟的加入下，可以诱导表面羧酸配体的交换。这些研究表明羧酸盐可能是促进团簇溶解成更大纳米结构的关键成分。为此，通过原位紫外-可见光谱研究了InP簇的演变，揭示了簇的溶解和再核与羧酸盐的浓度密切相关。除了外源配体的浓度外，颗粒的生长速度和最终产物的分布还取决于温度和初始簇浓度。综上所述，这些结果表明了一种涉及簇解离形成多个反应性单体物种的簇进化机制，这些单体物种可以再生并生长成更大的纳米材料。在较低温度下观察到非生产性单体降解(
Understanding and deconvoluting the different mechanisms involved in the synthesis of nanomaterials is necessary to make uniform materials with desirable function. In this study, in situ spectroscopic methods were used to study exchange reactions at the surface of indium phosphide clusters, revealing that the cluster surface lacks significant dynamics on the NMR time-scale at room temperature. The exchange of surface carboxylate ligands can be induced at elevated temperatures and with the addition of carboxylic acid and indium carboxylate. These studies suggest that carboxylate may be a key ingredient in promoting cluster dissolution to larger nanostructures. Toward this end, the evolution of InP clusters was examined by in situ UV-vis spectroscopy, revealing cluster dissolution and renucleation that is dramatically dependent on the concentration of carboxylate. In addition to the concentration of exogenous ligands, the rate of particle growth and final product distribution were dependent on temperature and initial cluster concentration. These results, taken together, suggest a mechanism of cluster evolution involving cluster dissociation to form multiple reactive monomer species that renucleate and grow to larger nanomaterials. Nonproductive monomer degradation is observed in the lower temperature regime (