Surface Functionalization of Ti₃C₂T MXene Nanosheets with Catechols: Implication for Colloidal Processing.

Area of Science:

• Materials Science
• Surface Chemistry
• Nanotechnology

Background:

• Tailoring two-dimensional nanosheets with organic molecules is crucial for surface passivation and reactivity control.
• MXenes (Ti3C2Tx) are promising 2D materials with diverse applications, but their surface properties require precise engineering.

Purpose of the Study:

• To introduce catechols for functionalizing exfoliated Ti3C2Tx MXene nanosheets in colloidal suspension.
• To investigate the binding mechanism, structural changes, and potential applications of catechol-functionalized MXenes.

Main Methods:

• Density Functional Theory (DFT) and UV-vis spectroscopy to confirm charge-transfer complex formation.
• X-ray diffraction (XRD) to analyze changes in interlayer spacing.
• Raman and Atomic Force Microscopy-Infrared (AFM-IR) spectroscopy to determine binding modes.
• Demonstration of fluorescent dye immobilization.

Main Results:

• Catechols spontaneously react with Ti3C2Tx surfaces via metal-oxygen bonds, forming a charge-transfer complex.
• Catechol functionalization increases the interlayer spacing of Ti3C2Tx MXene sheets.
• Successful immobilization of a fluorescent dye on the functionalized MXene surface was achieved.

Conclusions:

• Aqueous functionalization of MXene surfaces with catechols provides a versatile strategy for tailoring material properties.
• This method enhances colloidal stability and introduces anchoring points for further functionalization, such as polymer brush growth.
• The findings open avenues for developing advanced MXene-based materials with tunable characteristics.