Functionalization-Driven Formation of TiO₂/Ti₂CT _x Interfaces

Area of Science:

• Materials Science
• Surface Chemistry
• Computational Chemistry

Background:

• Titanium dioxide (TiO2) and MXene interfaces are promising for photoactive applications.
• Understanding the fundamental nature of these interfaces is crucial but challenging.

Purpose of the Study:

• To systematically investigate the interface characteristics between TiO2 and MXenes.
• To elucidate the role of MXene surface functionalization on TiO2/MXene interactions.
• To provide atomistic insights into the behavior of these emerging photoactive materials.

Main Methods:

• Density functional theory (DFT) calculations were employed.
• Ti2C was used as a representative MXene case study.
• Analysis of interface bonding, polarization, and charge transfer was performed.

Main Results:

• MXene surface functionalization dictates the TiO2/MXene interface nature.
• Strong chemical bonding occurs with unfunctionalized, -H, or -OH terminated Ti2C.
• Weak van der Waals interactions are observed for -F, -Cl, or -O terminated Ti2C.
• Charge transfer from MXene to TiO2 is localized at the interface and influenced by functionalization.

Conclusions:

• The study reveals distinct interaction mechanisms based on MXene termination.
• Findings offer critical atomistic understanding for designing advanced TiO2/MXene photoactive systems.
• This work advances the comprehension of emerging MXene-based composite materials.