Regulation of photoelectric properties of multi-element (Sn, Fe, Ce) co-doped anatase TiO2: The first principles study

Abstract

The energy band structure, density of states and optical properties of multi-element (Sn, Fe, Ce) co-doped anatase titanium dioxide have been calculated using the first principles method. The results show that two-element (Sn, Fe, Ce) doping affects the energy band structure more than the single doping behaviour. Co-doping of two of the three elements (Sn, Fe, Ce) reduced the energy band gap values of TiO2 compared to pure anatase TiO2.The forbidden bandwidths of Sn and Ce were smaller than those of mono-doped Sn, but the co-doped system had higher bandwidth narrowing than that of the mono-doped system. The co-doping of Sn and Ce is 0.206 eV smaller than the single doping of Sn, and the co-doping of Sn and Fe is 0.56 eV smaller than the single doping of Sn. The utilization of the regional light absorption is increased, and the absorption spectra are red-shifted. It can be seen that the co-doping method is more favourable to the improvement of visible light response and visible photocatalytic activity of TiO2 than the single doping method.