Surface processes of Np on selected mineral oxides. Vibrational spectroscopic investigations

Np 在选定的矿物氧化物上的表面过程。

• 批准号: 189921599
• 负责人: Dr. Katharina Müller
• 金额: --
• 依托单位: Institut für Ressourcenökologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2011
• 资助国家: 德国
• 起止时间: 2010-12-31 至 2013-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/189921599?language=en
• 关键词: Surface; processes; Np; selected; mineral

The structures of different interface complexes of neptunium (Np(V)) at mineral oxides are to be identified on a molecular level. The interface complexes will be studied under specific and environmentally relevant conditions by variation of selective parameters, such as pH or ionic strength of the solvent, and by the promotion of different surface complexation pathways. The structures of intermediate oligomeric, colloidal or precipitated molecule complexes were not determined so far, although there is scientific agreement about their occurrence. As major innovation of this project, the possible sorption processes, namely the development of monomeric and oligomeric surface complexes, and the formation of surface precipitates or surface colloids will be spectroscopically investigated. This in turn will allow a generalization of reaction patterns of chemically similar but experimentally difficult to access actinyl systems, e.g., Pa or Pu. In addition, the results will supply well-established quasithermodynamic sorption models with adequate approaches for competing processes such as surface precipitation. The processes will be mainly identified and characterized in aqueous solution by in situ ATR FT-IR spectroscopy. Because the characteristic frequencies of the vibrational modes of distinct functional groups, i.e. the neptunyl ion and the ubiquitous inorganic ligand such as the carbonate anion, are generally well separated in the infrared spectra, this technique will provide comprehensive molecular information of the interface processes. Complementary spectroscopic techniques, e.g. XAS and TRLFS, and microscopic methods, e.g. AFM and CLSM will also be applied.

镎（Np（V））在矿物氧化物上的不同界面络合物的结构将在分子水平上被识别。将在特定的和环境相关的条件下，通过改变选择性参数，如pH值或离子强度的溶剂，并通过促进不同的表面络合途径的界面络合物进行研究。中间低聚物、胶体或沉淀分子复合物的结构迄今尚未确定，尽管科学界对它们的出现达成了一致意见。作为该项目的主要创新，可能的吸附过程，即单体和低聚物表面络合物的发展，以及表面沉淀物或表面胶体的形成将进行光谱研究。这反过来将允许化学上类似但实验上难以获得的actinyl系统的反应模式的一般化，例如，爸或普。此外，研究结果将提供完善的准热力学吸附模型与充分的方法，如表面降水竞争过程。这些过程将主要通过原位ATR FT-IR光谱在水溶液中进行鉴定和表征。由于不同官能团的振动模式的特征频率，即镎基离子和无处不在的无机配体，如碳酸根阴离子，通常在红外光谱中分离良好，这种技术将提供全面的界面过程的分子信息。补充光谱技术，如XAS和TRLFS，和显微镜方法，如AFM和CLSM也将被应用。

项目成果

In situ spectroscopic identification of neptunium(V) inner-sphere complexes on the hematite-water interface.

• DOI: 10.1021/es5051925
• 发表时间: 2015-01
• 期刊: Environmental science & technology
• 影响因子: 11.4
• 作者: K. Müller;Annett Gröschel;A. Roßberg;F. Bok;C. Franzen;V. Brendler;H. Foerstendorf