高解像度電子顕微鏡を用いたMOF MIL-101の調節可能な結晶表面構造の直接イメージング
Xinghua Li1, Jianjian Wang2, Xin Liu3
1Physical Sciences and Engineering Division, Advanced Membranes and Porous Materials Center , King Abdullah University of Science and Technology (KAUST) , Thuwal 23955-6900 , Saudi Arabia.
Journal of the American Chemical Society
|July 20, 2019
まとめ
添加物はMIL-101のような金属有機フレームワーク (MOF) の表面構造と安定性に影響します. 直接的なイメージングは,明確な表面構造と,真空加熱がMOFケージの開口にどのように影響するか明らかにしました.
科学分野:
- 材料科学
- クリスタルグラフィー
- ナノテクノロジー
背景:
- メタル・オーガニック・フレームワーク (MOF) は,結晶化を制御するために添加物で合成された重要な多孔性材料です.
- MOFの表面構造を理解することは,その特性を様々な用途に合わせるための鍵です.
研究 の 目的:
- 異なる添加物で合成されたMOF MIL-101の表面構造を直接イメージし,特徴づけます.
- MIL-101の表面構造とフレームワークの安定性に対する真空加熱の影響を調査する.
- 合成添加物によって誘発される潜在的な相変換を観察する.
主な方法:
- 低用量高解像度伝送電子顕微鏡 (HRTEM) で,サブユニット細胞解像度で直接の表面イメージングを行う.
- 真空加熱中の構造の進化を監視するために,X線 difraktion (XRD) を用いる.
- フッ素酸を含む様々な添加物を用いたMIL-101の合成
主要な成果:
- MIL-101の水晶に 3つの異なる表面構造を特定した
- 真空加熱はMIL-101表面のメソポラスケージを開き,サンプル添加物に対する温度に依存することを観察した.
- HRTEMとin situ XRDの結果は良好な一致を示し,添加物が表面構造とフレームワークの安定性に影響することを示唆しました.
- フッ素酸で合成したサンプルでMIL-101からMIL-53への固体-固体相変換が観察された.
結論:
- 添加物はMOF MIL-101の表面形態と安定性に大きく影響する.
- 真空加熱はMIL-101の表面の多孔性を制御的に変化させる.
- フッ素酸はMIL-101における相変換を誘導し,合成条件の役割を強調する.
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