Ultimate Control over Hydrogen Bond Formation and Reaction Rates for Scalable Synthesis of Highly Crystalline vdW MOF Nanosheets with Large Aspect Ratio
Ultimate Control over Hydrogen Bond Formation and Reaction Rates for Scalable Synthesis of Highly Crystalline vdW MOF Nanosheets with Large Aspect Ratio
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DOI：
10.1002/adma.201802497
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发表时间：
2018-11
影响因子：
29.4
通讯作者：
Yuxia Shen;Bohan Shan;H. Cai;Ying Qin;A. Agarwal;Dipesh B. Trivedi;Bin Chen;Lei Liu;H. Zhuang;B. Mu;S. Tongay
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文献类型：
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作者：
Yuxia Shen;Bohan Shan;H. Cai;Ying Qin;A. Agarwal;Dipesh B. Trivedi;Bin Chen;Lei Liu;H. Zhuang;B. Mu;S. Tongay
大规模合成具有受控结晶度和层间耦合强度的范德华（vdW）金属有机框架（MOF）纳米片是二维材料的瓶颈之一，限制了其成功过渡到大规模应用。在这里，展示了通过双相方法大规模合成 mBDC（m = Zn 和 Cu）2D MOF。结果表明，用吡啶取代水分子消除了金属簇位点上氢键的形成。这阻止了相邻 MOF 层之间的紧密耦合，并维持可控的 2D vdW MOF 生长。进一步表明，通过添加受控量的三乙胺和甲酸可以实现对生长速度、结晶度和厚度的控制，从而获得具有极高长径比的高度结晶的 vdW MOF 纳米片。通过沉积到所需的基材上或以结晶层状粉末形式，所描述的合成路线可以很容易地扩大规模以进行大规模生产。由于其横向尺寸大、vdW 性质和高结晶度，可以在 2D MOF 上进行原子力显微镜、开尔文探针力显微镜和拉曼测量。结果不仅确定了它们的振动特性和层相关响应，而且还显示出与其他二维无机材料的显着差异。
Large‐scale synthesis of van der Waals (vdW) metal–organic framework (MOF) nanosheets with controlled crystallinity and interlayer coupling strength is one of the bottlenecks in 2D materials that has limited its successful transition to large‐scale applications. Here, scalable synthesis of mBDC (m = Zn and Cu) 2D MOFs at large scales through a biphase method is demonstrated. The results show replacing water molecules with pyridine eliminates hydrogen bond formation at metal cluster sites. This prohibits tight coupling across adjacent MOF layers and sustains controllable 2D vdW MOF growth. It is further shown that control over the growth speed, crystallinity, and thickness can be achieved by addition of a controlled amount of triethylamine and formic acid to achieve highly crystalline vdW MOF nanosheets with extraordinarily high aspect ratio. The described synthesis route can easily be scaled up for large‐scale production either by deposition onto desired substrates or in crystalline layered powder form. Owing to its large lateral size, vdW nature, and high crystallinity, it is possible to perform atomic force microscopy, Kelvin probe force microscopy, and Raman measurements on the 2D MOFs. The results not only establish their vibrational properties and layer‐dependent responses but also show striking differences from other 2D inorganic materials.