| 초록 |
Titania (TiO 2 ) photocatalysts, each embedded with one of six metals (Ag, Ce, Co, Fe, Mg, and Mn), were prepared using a simplified ultrasonic process. The characteristics of the prepared metal-embedded TiO 2 (metal-TiO 2 ) were determined using transmission electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction spectroscopy, photoluminescence emission spectroscopy, UV-visible spectroscopy, and nitrogen adsorption-desorption. Except for Co-TiO 2 , the metal-TiO 2 photocatalysts showed improved performance for the decomposition of gaseous benzene and toluene, which are two of the most problematic indoor air pollutants that can cause a variety of adverse health symptoms, under daylight lamp irradiation. Photocatalytic activity was greatest for the Mg-TiO 2 sample, followed by, in order, the Ag-TiO 2 , Ce-TiO 2 , Fe-TiO 2 , Mn-TiO 2 , unmodified TiO 2 , and Co-TiO 2 samples. Although Mg-TiO 2 showed the least redshift in its light absorption and the highest electron-hole recombination rate among the metal-TiO 2 photocatalysts, it yielded the highest photocatalytic activity, likely because of its increased adsorption capacity and anatase composition. The degradation of benzene and toluene over Mg-TiO 2 improved as ultrasound treatment amplitude increased from 20 to 37 mu;m, then decreased gradually as amplitude was further increased to 49 mu;m. Degradation efficiency also improved as ultrasound operation time increased from 30 to 60min, then decreased gradually as amplitude was further increased to 90min. Overall, this process could be utilized to prepare metal-TiO 2 photocatalysts with improved performance for the decomposition of gas phase pollutants under daylight lamp irradiation. |
