Aalling-Frederiksen Olivia, Juelsholt Mikkel, Anker Andy S, Jensen Kirsten M Ø
Department of Chemistry and Nano-Science Center, University of Copenhagen, 2100 Copenhagen Ø, Denmark.
Nanoscale. 2021 May 7;13(17):8087-8097. doi: 10.1039/d0nr08299f. Epub 2021 Mar 23.
Understanding the mechanisms for nanoparticle nucleation and growth is crucial for the development of tailormade nanomaterials. Here, we use X-ray total scattering and Pair Distribution Function analysis to follow the formation and growth of niobium oxide nanoparticles. We study the solvothermal synthesis from niobium chloride in benzyl alcohol, and through investigations of the influence of reaction temperature, a formation pathway can be suggested. Upon dissolution of niobium chloride in benzyl alcohol, octahedral [NbClO] complexes form through exchange of chloride ligands. Heating of the solution results in polymerization, where larger clusters built from multiple edge-sharing [NbClO] octahedra assemble. This leads to the formation of a nucleation cluster with the ReO type structure, which grows to form nanoparticles of the Wadsley-Roth type H-NbO structure, which in the bulk phase usually only forms at high temperature. Upon further growth, structural defects appear, and the presence of shear-planes in the structure appears highly dependent on nanoparticle size.
了解纳米颗粒成核和生长的机制对于定制纳米材料的开发至关重要。在此，我们使用X射线全散射和对分布函数分析来跟踪氧化铌纳米颗粒的形成和生长。我们研究了在苄醇中由氯化铌进行的溶剂热合成，并通过研究反应温度的影响，提出了一种形成途径。氯化铌溶解在苄醇中后，通过氯配体的交换形成八面体[NbClO]配合物。溶液加热导致聚合，由多个共边[NbClO]八面体构成的较大簇聚集在一起。这导致形成具有ReO型结构的成核簇，其生长形成Wadsley-Roth型H-NbO结构的纳米颗粒，而这种结构在体相中通常只在高温下形成。进一步生长时，会出现结构缺陷，并且结构中剪切面的存在似乎高度依赖于纳米颗粒的尺寸。
