Development of Visible Light Sensitive Titanium Dioxide Loaded with Fe₂O₃ Nanoparticles and Evaluation of their Photocatalytic Activities

Abstract

We have succeeded in preparing doped TiO₂ powders after the calcinations of the mixture TiO₂ and organic compounds such as urea or thiourea. In order to improve the photoactivity of the doped TiO₂, we investigated the doped TiO₂ loaded with Fe₂O₃ nanoparticles. The photoactivities of doped TiO₂ loaded with Fe₂O₃ nanoparticles for decomposition of 2-propanol and acetaldehyde were higher than that of doped TiO₂ without Fe₂O₃ nanoparticles. ESR analyses suggested that photoexcited electrons generated in TiO₂ during photoirradiation were efficiently trapped by Fe³⁺ ions loaded on TiO₂, which resulted in the formation of Fe²⁺ ions. When the doped TiO₂ photocatalysts loaded with Fe₂O₃ nanoparticles was treated with NaBH₄ and air oxidation, their photocatalytic activities were 1.5 times that of the one without the treatment of NaBH₄. The improvement of photocatalytic activity was due to a decrease in diameter of Fe₂O₃ nanoparticles on the doped TiO₂, which was supported by the results of TEM and EDX analyses.