Exploring Novel Interfacial Charge Transfer Complexes Between TiO₂ and Flavonoids: Theoretical Study.

Area of Science:

• Materials Science
• Computational Chemistry
• Quantum Chemistry

Background:

• Titanium dioxide (TiO2) materials have limited spectral properties.
• Interfacial charge transfer (ICT) complexes offer a route to enhance material properties.
• Flavonoids are natural compounds with known antioxidant activities.

Purpose of the Study:

• To investigate the potential of six different flavonoids as ligands for creating novel TiO2-based ICT complexes.
• To computationally assess the stability and spectral properties of these new complexes.
• To evaluate the antioxidant potential of the synthesized TiO2-flavonoid complexes.

Main Methods:

• Density Functional Theory (DFT) calculations were employed.
• Bader's Quantum Theory of Atoms in Molecules (QTAIM) analysis confirmed coordination.
• Thermochemistry calculations assessed radical scavenging potential.

Main Results:

• Stable bidentate Ti-O coordination was confirmed between TiO2 and flavonoids.
• Calculated band gaps for ICT complexes ranged from 1.95-2.15 eV, significantly lower than pristine TiO2 (3.20 eV).
• Flavonoids with an OH group at position 3 of the C ring (myricetin, quercetin) yielded the lowest band gaps, enabling visible light absorption.
• The formed ICT complexes exhibited enhanced radical scavenging potential compared to parent flavonoids.

Conclusions:

• TiO2-based ICT complexes synthesized with flavonoids demonstrate improved spectral properties, enabling visible light absorption.
• These novel complexes possess superior antioxidant capabilities compared to the original flavonoids.
• The findings suggest potential applications for these enhanced TiO2-flavonoid materials.