Abstract:CaTiO₃-Fe_x was characterized by X-ray diffractometry, scanning electron microscopy equipped with an energy dispersive spectrometry system, Fourier transform infrared spectra, and UV-visible spectra. Effects of Fe content on photocatalytic activity of CaTiO₃-Fe_x were investigated through measuring photocatalytic degradation rate of methylene blue. The results show that chemical compositions of CaTiO₃-Fe_x remained unchanged with increasing Fe content from 0 to 4.745%. However, the light absorption ability of CaTiO₃-Fe_x exhibited a significant increase with increasing Fe content. Photocatalytic degradation of methylene blue over CaTiO₃-Fe_x followed the first-order reaction kinetics. Based on changes of the concentration of methylene blue and its degradation kinetics, CaTiO₃-Fe_0.474% has shown to have optimal photocatalytic activity. The degradation rate of methylene blue over CaTiO₃-Fe_0.474% was almost 100% under UV-visible light irradiation for 3.0 h. The k_obs of methylene blue over CaTiO₃-Fe_0.474% was 1.33 h^-1 and was 7 times that over CaTiO₃-Fe₀.

Key words: CaTiO₃-Fe_x; methylene blue; photocatalytic activity; kinetics