CAJ | 학술논문

Nanometer perovskite-type oxides MgTiO_3, CaTiO_3, SrTiO_3 were prepared using tetrabutyl titanate, alkaline earth metal nitrates as raw materials by sol-gel method. The samples were characterized by thermogravimetry - differential thermal (TG-DTA), X-ray diffraction (XRD), UV-Vis spectrophotometer (UV-Vis) and X-ray photoelectron spectroscopy (XPS). Using methylene blue as a degradation target, we studied that calcination temperature had an impact on photocatalytic activity of three different photocatalysts. Through the photocatalytic degradation of methylene blue, photocatalytic activity of the three perovskite-type catalysts was compared. The results showed that different crystal structure resulted in different temperature of optimum activity. The temperature of best photocatalytic activity for MgTiO_3 was 700℃, CaTiO_3 and SrTiO_3 were 800℃. In the above-mentioned catalyst, CaTiO_3 had the highest photocatalytic activity. XPS analysis and catalytic reaction with O_2 show that the surface oxygen absorbed capacity is the most important factor which has an influence on photocatalytic activity of three perovskite-type photocatalysts.