The Molecular Mechanism of Iron(III) Oxide Nucleation.
The Molecular Mechanism of Iron(III) Oxide Nucleation.
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DOI：
10.1021/acs.jpclett.6b01237
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发表时间：
2016-08
期刊：
影响因子：
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通讯作者：
Johanna Scheck;Baohu Wu;M. Drechsler;R. Rosenberg;A. V. Van Driessche;T. Stawski;D. Gebauer
中科院分区：
文献类型：
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作者：
Johanna Scheck;Baohu Wu;M. Drechsler;R. Rosenberg;A. V. Van Driessche;T. Stawski;D. Gebauer
从分子水平上理解溶液中固相的形成，将对各个科学领域都有好处。然而，成核途径仍然没有完全理解，其中铁（氧氢）氧化物的情况下构成一个主要的例子。我们发现，在prenucleation制度，结晶稳定的溶质物种的大小可达几个纳米，这符合prenucleation集群的定义。然后，成核不受临界尺寸的控制，而是由在不同成核阶段形成的簇的动力学控制，基于簇内的键的化学性质。这解决了铁氧化物成核领域的长期争论，并且结果通常可以适用于通过水解和缩合形成的氧化物。对相分离的化学基础的（分子）理解对于例如，定制尺寸、形状和结构的新型纳米晶材料。
A molecular understanding of the formation of solid phases from solution would be beneficial for various scientific fields. However, nucleation pathways are still not fully understood, whereby the case of iron (oxyhydr)oxides poses a prime example. We show that in the prenucleation regime, thermodynamically stable solute species up to a few nanometers in size are observed, which meet the definition of prenucleation clusters. Nucleation then is not governed by a critical size, but rather by the dynamics of the clusters that are forming at the distinct nucleation stages, based on the chemistry of the linkages within the clusters. This resolves a longstanding debate in the field of iron oxide nucleation, and the results may generally apply to oxides forming via hydrolysis and condensation. The (molecular) understanding of the chemical basis of phase separation is paramount for, e.g., tailoring size, shape and structure of novel nanocrystalline materials.