Abstract: The band structures, electronic density of states and optical properties of Hf-doped, Ta-doped, and W-doped TiO2 systems are computed by the first-principles based on density functional theory .The results show that the impurity leads tolargen the doped systems volumeas the impurity concentration increases.The doped systemsbandgap is less than that of pure TiO2 .From the band structure graphs of the Ta-doped, and W-doped TiO2 systems,it is found that the bottom of conduction band is under the Fermi level, as is known that the two kinds of doped systems are N-type semiconductor .With the various concentrations of Hf/Ta/W being doped in the TiO2 systems , the absorption spectrums of all the doped systems exhibitvarying degrees of red shift , and the light response range of Ta-doped, and W-doped TiO2 systems covers the entire visible area .Especially, the light responsiveness of Ti 0.9375 W0.0833 O2 in the visible region is the strongest .In a word, the impurity atoms ( Hf, Ta, W ) doped greatly improves the photocatalysis of the Anatase TiO2 .

Key words: The band structures, electronic density of states and optical properties of Hf-doped, Ta-doped, and W-doped TiO2 systems are computed by the first-principles based on density functional theory .The results show that the impurity leads tolargen the doped systems volumeas the impurity concentration increases.The doped systemsbandgap is less than that of pure TiO2 .From the band structure graphs of the Ta-doped, and W-doped TiO2 systems,it is found that the bottom of conduction band is under the Fermi level, as is known that the two kinds of doped systems are N-type semiconductor .With the various concentrations of Hf/Ta/W being doped in the TiO2 systems , the absorption spectrums of all the doped systems exhibitvarying degrees of red shift , and the light response range of Ta-doped, and W-doped TiO2 systems covers the entire visible area .Especially, the light responsiveness of Ti 0.9375 W0.0833 O2 in the visible region is the strongest .In a word, the impurity atoms ( Hf, Ta, W ) doped greatly improves the photocatalysis of the Anatase TiO2 .