In recent years, photocatalysts have been used in various fields, and are particularly attracting attention in the fields of environment, medicine, and agriculture. A large number of catalytic active sites are required to produce a more efficient photocatalyst, and for that purpose, a large specific surface area is desired. Therefore, in this study, in order to develop a highly active photocatalytic material, the outer diameter of titanium oxide nanotubes was controlled by a template synthesis method using carbon nanotubes with different outer diameters to increase the specific surface area. Characterization was carried out by using diffent analytical instruments such as UV-Spectrophotomoter, XRD, SEM, TEM, BET. Results show using titanium oxide nanotubes with a smaller outer diameter tended to have higher photocatalytic activity (almost complete degradation was obtained when 10-20nm was used).

The conditions for photocatalytic degradation of ethylenediaminetetraacetic acid (EDTA) in aqueous solution with Fe-doped titanium dioxide (TiO2) were optimized. The degradation efficiencies with Fe-doped TiO2 were better, compared with those obtained with bare TiO2 and Pt-doped TiO2. The effect of various experimental factors, such as photocatalytic dosage, temperature, solution pH and light intensity on the photocatalytic degradation of EDTA by Fe-doped TiO2 was investigated. The photocatalytic degradation treatment for the wastewater containing EDTA is simple, easy handling and low cost.