Cite this article as: |
Peng Sun, Sumei Han, Jinhua Liu, Jingjing Zhang, Shuo Yang, Faguo Wang, Wenxiu Liu, Shu Yin, Zhanwu Ning, and Wenbin Cao, Introducing oxygen vacancies in TiO2 lattice via trivalent iron to enhance photocatalytic removal of indoor NO, Int. J. Miner. Metall. Mater.,(2023). https://doi.org/10.1007/s12613-023-2611-z |
The synthesis of oxygen vacancies (OVs) modified TiO2 under mild conditions is attractive. In this work, OVs were easily introduced in TiO2 lattice during the hydrothermal doping process of trivalent iron ions. Theoretical calculations based on a novel charge-compensation structure model were employed with experimental methods to reveal the intrinsic photocatalytic mechanisms of Fe doped TiO2 (Fe-TiO2). The OVs’ formation energy in Fe-TiO2 (1.12 eV) was only 23.6% of that in TiO2 (4.74 eV), explaining why Fe3+ doping could introduce OVs concentration in TiO2 lattice. The calculation results also indicated that impurity states introduced by Fe3+ and OVs enhanced the light absorption activity of TiO2. Additionally, the charge carriers’ transport was investigated by carriers’ lifetime and relative mass. The carriers’ lifetime of Fe-TiO2 (4.00 ns, 4.10 ns and 3.34 ns for 1%, 2% and 3% doping concentration, respectively) was longer than that of undoped TiO2 (3.22 ns), indicating Fe3+ and OVs could promote the separation of charge carriers, which can be attributed to the bigger relative effective mass of electrons and holes. Herein, the Fe-TiO2 has higher photocatalytic indoor NO removal activity compared with other photocatalysts because it has strong light absorption activity and high carriers’ separation efficiency.