Metallurgical Abstracts on Light Metals and Alloys vol.57
Electronic structure analysis of light-element-doped anatase TiO2 using all-electron GW approach
Takashi Ishikawa1, Ryoji Sahara2, Kaoru Ohno3, Kyosuke Ueda1 and Takayuki Narushima1
1 Department of Materials Processing, Tohoku University
2 Research Center for Structural Materials, National Institute for Materials Science
3 Graduate School of Engineering, Yokohama National University
[Published in Computational Materials Science, Vol. 220 (2023), 112059]
https://doi.org/10.1016/j.commatsci.2023.112059
E-mail: ueda [at]material.tohoku.ac.jp
Key Words: photocatalysis, anatase TiO2, light element doping, visible light, All-electron mixed basis approach
A new structural phase of anatase TiO2 codoped with C and N with a relatively low band gap was discovered. Phase stability was first analyzed using density functional theory calculations by considering interstitial and substitutional positions and oxygen vacancies. The stable defect states were found to depend on the oxygen (O2) pressure conditions or oxygen chemical potential in C and N monodoped and codoped TiO2. Thereafter, the all-electron GW approach based on many-body perturbation theory was adopted to determine the electronic structures and understand the band gap narrowing mechanism. The band gap could be controlled by varying the oxygen pressure and doping states, and the band gap narrowing due to C, N codoping was more than that due to monodoping. Under an intermediate oxygen pressure condition, the band gap of TiO2 codoped with C and N was found to be 2.28 eV. Therefore, TiO2 codoped with C and N can be used as a visible-light-response photocatalyst.
