多核固态NMR光谱中的MAX和MXene阶段的批量和表面化学
Kent J Griffith1,2, Michael A Hope1, Philip J Reeves1
1Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, United Kingdom.
Journal of the American Chemical Society
|October 23, 2020
概括
固态NMR光谱显示 (Nb) MXene相上的混合氧化物和化物终结. 这种多核方法识别无形杂质,提供了对MAX和MXene化学的更深入的见解.
科学领域:
- 材料科学
- 固态化学
- 光谱学
背景情况:
- 由MAX相衍生而来的二维MXenes具有有前途的应用,但其表面化学结构尚未完全理解.
- 固态核磁共振 (NMR) 光谱对界面化学和相位纯度敏感.
研究的目的:
- 使用多核固态NMR系统地研究 (Nb) MAX和MXene相的化学成分.
- 识别表面终点和描述相组成,包括无形或纳米晶体杂质.
主要方法:
- 对Nb MAX和MXene相的系统研究 (Nb2AlC,Nb4AlC3,Nb2CTx,Nb4C3Tx).
- 多核固态NMR光谱 (1H, 13C, 19F, 27Al, 93Nb) 进行了各种实验.
- 对过渡金属共振的分析和与其他MXenes的比较.
主要成果:
- 在Nb MXene相上确定了密切混合的氧化物和化物终结.
- 证明仅仅衍射不足以进行相位组合分析,揭示了许多无形/纳米晶相 (例如,NbC,AlF3·nH2O,Nb金属).
- 在MXenes中实现了第一个直接的过渡金属NMR和第一个在任何MAX阶段的93NbNMR,从而实现了Ti3AlC2NMR频谱的分配.
结论:
- 固态NMR提供了对MAX和MXene化学的基本见解,补充了衍射方法.
- 这种方法可以更全面地了解MAX和MXene阶段.
- 结果可以为计算选和属性分析准备现实的结构模型.
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