Oxygen vacancy and Ti3+ self-doped TiO2 nanorods for boosting visible-light-driven photocatalytic activity

Document Type : Research Article

Authors
Ali Baqaei 1
Ali Asghar Sabbagh Alvani 2
Hassan Sameie 3
1 Color and polymer research center, Amirkabir University
2 Amirkabir University of Technology
3 Color & Polymer Research Center
10.22034/amnc.2024.412715.1248
Abstract
Titanium dioxide shows limited efficiency due to its wide energy gap and fast recombination of charge carriers, and considering its high light harvesting potential, it can be attempted to narrow its energy band gap by creating surface defects. Therefore, in this study, an effort was made to create surface defects, oxygen vacancy (OV), and Ti3+, which lead to the formation of mid-gap states in the TiO2 energy gap, by reducing rutile titanium dioxide nanorods, which is prepared by hydrothermal method, in the presence of gas flow. During the reduction process, no changes were observed in the crystal phase and orientation of the nanorods, which was confirmed by XRD and FESEM results. The reduction process caused the red-shift of the TiO2-x absorption edge towards the visible region (511 nm), and the formation of OV and Ti3+ effectively narrowed the energy gap from 2.95 to 2.42 ev, while the creation of the mid-gap states reduced the e-h recombination, enhanced the charge carrier’s lifetime and so improved the photocatalytic activity of the TiO2-x nanorods.
Keywords
Synthesis
Photocatalyst
Titanium dioxide
Oxygen vacancy
Nanorods
Subjects