Preparation and Photocatalytic Activity Evaluation of Composite Fe-TiO2/TiO2 Photocatalyst

Fe-TiO2 photocatalyst was prepared by a sol-gel method using tetrabutyl titanate [Ti(OC4H9)(4)] as the titanium precursor. The composite photocatalyst Fe-TiO2/TiO2 was prepared by the ballmilling method. The structure and properties of the samples were characterized by X-ray powder diffraction, UV/visible diffuse reflectance spectroscopy, X-ray photoelectron spectroscopy, and photoluminescence (PL) emission spectroscopy. The terephthalic acid was used as a probe molecule to detect the generation of hydroxyl radicals (center dot OH) on the surface of UV-illuminated photocatalyst by a PL technique. The results showed that doping Fe3+ into TiO2 is more beneficial toward the photocatalytic reduction rather than oxidation with the optimum amount level of 0.05% (Fe/Ti molar ratio). After coupling between Fe-TiO2 and TiO2, both the photo-oxidation and photoreduction activities of the sample are enhanced. Among the composite Fe-TiO2/TiO2 samples, the Fe-TiO2 (5.0 wt %)/TiO2 sample exhibits the best photocatalytic activity. It is proposed that the photo-oxidation and photoreduction activities are promoted by coupling Fe-TiO2 and TiO2 as a homojunction where the photoexcited holes and electrons are separated effectively.