The structure, electronic, and optical properties of (Sm,N)-codoped anatase TiO2 photocatalyst: A density functional study

The geometrical, electronic, and optical properties of Sm-doped, N-doped, and (Sm,N)-codoped anatase TiO2 were successfully calculated and simulated using the spin-polarized density functional theory. The researches of geometrical structures show that (Sm,N) codoping leads to lattice distortion, which reduces the recombination of the photogenerated electron–hole pairs. Moreover, the calculated results indicate that the synergistic effects of (Sm,N) codoping can lead to an obvious band gap narrowing and a N 2p state appearing in the forbidden gap, which leads to a significant redshift of the optical absorption edge and enhances the photocatalytic activity of the (Sm,N)-codoped anatase TiO2.