First-principles study of Sc-doping effect on the stability, electronic structure and photocatalytic properties of Sr2TiO4

• Published in: Thin solid films 2013-09, Vol.542, p.276-280
• Main Authors: Yun, J.N., Zhang, Z.Y., Yan, J.F., Zhao, W.
• Format: Article
• Language: English
• Subjects: Chemistry; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Density functional theory; Dispersions; Doping; Electron states; Electronic structure; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Electronic transport phenomena in thin films and low-dimensional structures; Exact sciences and technology; General and physical chemistry; General, apparatus; Lattice parameters; Layered perovskite oxide; Mathematical analysis; Methods of electronic structure calculations; Photocatalysis; Photocatalytic properties; Physics; Stability; Surface and interface electron states; Surface physical chemistry; Surface states, band structure, electron density of states; Transition metal doping
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/j.tsf.2013.06.067

The stability, electronic structure and photocatalytic properties of the Sc-doped Sr2TiO4 are investigated by first-principles calculations based on the density functional theory. The calculated results reveal that due to the electronic changes from doping, the stability of Sr2Sc0.125Ti0.875O4 is weakened after Sc doping. Meanwhile, because the increase value of lattice parameter a is larger than that of lattice parameter c, the value of c/a decreases to 3.209 and is smaller than that of undoped Sr2TiO4. The band gap of Sr2Sc0.125Ti0.875O4 has a narrowing about 0.25eV compared with that of undoped Sr2TiO4, resulting in the red-shift of absorption spectra edge. Particularly, the dispersion of the conduction bands and valence bands of Sr2Sc0.125Ti0.875O4 is enhanced after doping, which is preferable for the photocatalytic performance. In addition, a new weak absorption appears in the visible light region, which would somehow contribute to the photocatalytic activity of Sr2Sc0.125Ti0.875O4. •The Sc-doped Sr2TiO4 are thermodynamically stable.•The dispersion of the band structure of Sr2Sc0.125Ti0.875O4 is enhanced.•A new weak absorption appears in the visible light region.•The Sc doping can contribute to the photocatalytic activity of Sr2Sc0.125Ti0.875O4.