Preparation of Ca-doped LaFeO_3 nanopowders in a reverse microemulsion and their visible light photocatalytic activity

摘要

Nanoparticles of lanthanum ferrite (LaFeO_3) and calcium-doped LaFeO_3 (La_(1-x)Ca_xFeO_3,x = 0.05-0.20) with perovskite-type structure have been prepared in a reverse microemulsion. Perovskite powder could be obtained at 500 ℃ for 3 h. The prepared powders were characterized by thermogravimetry-differential thermal analysis (TG-DTA), X-ray diffraction (XRD) and UV-Vis absorption spectroscopy. The visible-light photocatalytic activity of the photocatalysts was tested with methylene blue as an objective decomposition substance using fluorescence light as a visible light resource. The results showed that partial substitution of La~(3+) in LaFeO_3 with Ca~(2+) could decrease the crystalline size, enhance visible light absorption and improve visible light photocatalytic activity.