Magnetic properties and photocatalytic activity of ZnFe2-x La (x) O-4 nanoparticles synthesized by sol-gel autocombustion method

摘要

Sol-gel autocombustion technique was employed to synthesize ZnFe2-x La (x) O-4 (0 < x < 0.2) nanoparticles. Cation distribution among the tetrahedral and octahedral sites and optical properties is highly dependent on La substitution in the spinel structure which was examined by X-ray diffraction, Raman spectroscopy and diffuse reflectance spectroscopy. The ZnFe2-x La (x) O-4 nanoparticles exhibited strong absorption in the visible region with the optical band gap calculated from Tauc's plot in the range of 1.93-1.98 eV. Furthermore, the effects of La substitution on the photodegradation of the methyl orange (MO) under visible light were also studied. The degradation of MO dye was enhanced with increasing La3+ substitution from x = 0 to x = 0.2, which may be due to the higher redox potential of La3+ ion as compared to those of iron. Moreover, the magnetic measurements showed that the magnetization decreased from 7.06 to 2.35 emu/g with La additions, due to the reduction in the total magnetic moments.