Preparation and characterization of visible light sensitive Fe- and Ta-codoped TiO₂ photocatalyst

Titania (TiO₂) was modified by codoping of Fe³⁺ and Ta⁵⁺ to absorb visible light. The codoped titania [(Fe,Ta)_xTi_1–xO₂, 0 ≤ x ≤ 1] were prepared by a solid state reaction or by the polymer complex method. With increased codoping, the optical absorption spectra are red-shifted and the color ranges from white to brown via yellow. Also, the codoped titania (0 < x ≤ 0.05) possesses photocatalytic activity for organic decomposition under visible light irradiation. The codoped titania (x = 0.01) with yellow color shows the highest activity among the codoped titania (0 ≤ x ≤ 1) and a higher activity than the 1% Fe³⁺-doped TiO₂ with orange brown color.