First-principles study on the synergistic effects of Mo–C codoped anatase TiO2

Electronic and optical properties of pure, C-doped, Mo-doped, and Mo–C codoped anatase TiO2 were investigated by the first principle calculations. The calculated results demonstrated that the incorporation of Mo into the C-doped TiO2 changes the character of C 2p states from unoccupied to occupied states, which will prevent the recombination of photogenerated electron–hole pairs. The optical absorption edge of Mo–C codoped TiO2 presents an obvious redshift due to the synergistic effects of Mo and C codoping and the obtained band gap is about 2.35 eV. The strong covalent coupling between Mo and C in codoped TiO2 may be responsible for the narrowed band gap and the enhanced visible light absorption.