Photocatalytic Activity of TiO(2)-Doped Fe, Ag, and Ni with N under Visible Light Irradiation

Doping with noble metal ions or doping with nitrogen has been attempted to prepare TiO(2) that reacts even in visible light. In this study, TiO(2) was doped with nitrogen and various metal ions instead of noble metals. The TiO(2) photocatalysts doped with metal ions (Fe, Ag, Ni) and nitrogen were prepared by a sol-gel method. Their physicochemical properties were characterized and their photocatalytic activities were investigated under visible light irradiation. In TiO(2) doped with metal ions and nitrogen, the light absorption region was extended to visible light. The photoluminescence intensity was much greater in N/Ni/TiO(2) than in N/Ag/TiO(2) and N/Fe/TiO(2). The photolysis activities of N/Ni/TiO(2) were the highest in formaldehyde decomposition and methylene blue decomposition. The sterilization efficiency of N/Ni/TiO(2) was the highest in the evaluation test for the inhibition of the proliferation of Pseudomonas aeruginosa. The bandgap of N/Ni/TiO(2) was 2.4 eV, which was significantly lower than that of anatase TiO(2) (3.2 eV). The N/Ni/TiO(2) had a much higher optical intensity than other metal ion-doped TiO(2), so it was highly active under visible light irradiation.