Heckler James E, Neher Gregory R, Mehmood Faisal, Lioi David B, Pachter Ruth, Vaia Richard, Kennedy W Joshua, Nepal Dhriti
ARCTOS Technology Solutions, 1270 N Fairfield Road, Beavercreek, Ohio 45432-2600, United States.
Materials and Manufacturing Directorate, Air Force Research Laboratory, 2941 Hobson Way, WPAFB, Ohio 45433, United States.
Langmuir. 2021 May 11;37(18):5447-5456. doi: 10.1021/acs.langmuir.0c03078. Epub 2021 Apr 30.
Precise tailoring of two-dimensional nanosheets with organic molecules is critical to passivate the surface and control the reactivity, which is essential for a wide range of applications. Herein, we introduce catechols to functionalize exfoliated MXenes (TiCT) in a colloidal suspension. Catechols react spontaneously with TiCT surfaces, where binding is initiated from a charge-transfer complex as confirmed by density functional theory (DFT) and UV-vis. TiCT sheet interlayer spacing is increased by catechol functionalization, as confirmed by X-ray diffraction (XRD), while Raman and atomic force microscopy-infrared spectroscopy (AFM-IR) measurements indicate binding of catechols at the TiCT surface occurs through metal-oxygen bonds, which is supported by DFT calculations. Finally, we demonstrate immobilization of a fluorescent dye on the surface of MXene. Our results establish a strategy for tailoring MXene surfaces via aqueous functionalization with catechols, whereby colloidal stability can be modified and further functionality can be introduced, which could provide excellent anchoring points to grow polymer brushes and tune specific properties.
用有机分子精确剪裁二维纳米片对于钝化表面和控制反应活性至关重要，这对于广泛的应用来说必不可少。在此，我们引入儿茶酚以在胶体悬浮液中对剥离的MXenes（TiCT）进行功能化。儿茶酚与TiCT表面自发反应，如密度泛函理论（DFT）和紫外可见光谱所证实，其结合从电荷转移复合物开始。如X射线衍射（XRD）所证实，儿茶酚功能化使TiCT片层间距增加，而拉曼光谱和原子力显微镜 - 红外光谱（AFM - IR）测量表明儿茶酚在TiCT表面的结合通过金属 - 氧键发生，这得到了DFT计算的支持。最后，我们展示了荧光染料在MXene表面的固定化。我们的结果建立了一种通过用儿茶酚进行水相功能化来剪裁MXene表面的策略，借此可以改变胶体稳定性并引入进一步的功能，这可为生长聚合物刷和调节特定性能提供优良的锚定位点。
