Photocatalytic activities of LaFe1−xZnxO3 nanocrystals prepared by sol–gel auto-combustion method

Nanophotocatalysts LaFe1−xZnxO3 (x = 0, 0.05, 0.1, 0.3, 0.5) were successfully prepared by sol–gel auto-combustion method. The samples were characterized by X-ray diffraction (XRD), ultraviolet/visible absorption spectra (UV–vis), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The photocatalytic activities of the prepared samples were investigated for the photodegradation of methylene blue (MB). The results show that the lattice constant of LaFe1−xZnxO3 nanocrystals increases due to the substitution of Zn for Fe, which leads to the lattice distortion. The absorption edges of Zn-doped LaFeO3 display a red shift with a significant absorption between 400 and 500 nm. Doping with the Zn ions enhances the photodegradation rate of LaFeO3 for MB. The LaFe0.7Zn0.3O3 particles are spherical with mean grain size of about 20–30 nm, which exhibits the highest degradation rate of 75% under irradiation time of 150 min.