Functionalization-Driven Formation of TiO2/Ti2CT x Interfaces

TL;DR

This study explores how different surface treatments of MXene materials affect their interaction with TiO2, revealing how chemical bonding and charge transfer occur at their interface.

Contribution

The study provides new atomistic insights into how MXene functionalization influences the formation and properties of TiO2/MXene interfaces.

Findings

Strong chemical bonding occurs at TiO2/Ti2C interfaces when MXene is not functionalized or terminated with -H or -OH.

Weak van der Waals interactions are observed with -F, -Cl, or -O functional groups on MXene surfaces.

Charge transfer from MXene to TiO2 is influenced by the functionalization of the MXene surface.

Abstract

In this study, the nature of the interface between TiO2 and MXenes was systematically explored by using density functional
theory and taking Ti2C as a case study. TiO2/MXene interfaces are emerging as potential photoactive systems,
but a deep understanding of their nature is often elusive. Our findings
reveal that MXene surface functionalization predominantly governs
the interaction between TiO2 and MXenes. Specifically,
when the Ti2C MXene is terminated with −H or −OH
or when it is not functionalized, the formation of the interface leads
to a strong interaction due to the formation of new chemical bonds.
Weak van der Waals interactions are present when the Ti2C MXene surface termination involves −F, −Cl, or −O
groups. The analysis of the interface polarization shows a systematic
charge transfer from MXene surfaces toward TiO2, which
is localized at the interface and influenced by MXene functionalization.
The results of this study provide new atomistic insights on the interaction
between these two materials, helping the understanding of the nature
of this emerging class of photoactive materials.

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