Preparation of ZnFe2O4 nanoparticles by mechanical alloying and annealing for sensitizing C-modified TiO2 and acquirement of efficient photocatalyst

Abstract

ZnFe2O4 nanoparticles sensitized by C-modified TiO2 hybrids (ZnFe2O4–TiO2/C) were successfully prepared by a feasible method. The ZnFe2O4 nanoparticles were prepared by mechanical alloying and annealing. The residual organic compounds in the synthetic process of TiO2 were selected as the carbon source. The as-prepared composites were characterized by X-ray diffraction, Raman spectroscopy, X-ray fluorescence, transmission electron microscopy, X-ray photoelectron spectroscopy, ultraviolet–visible light diffuse reflectance spectroscopy (UV–Vis) and N2 adsorption–desorption analysis. The photocatalytic activity of the photocatalysts was measured by degradation of methyl orange under ultraviolet (UV) light and simulated solar irradiation, respectively. The results show that the carbon did not enter the TiO2 lattice but adhered to the surface of TiO2. The photocatalytic activity of the as-prepared C-modified TiO2 (TiO2/C) improved both under UV and simulated solar light irradiation, but the improvement was not dramatic. Introduction of ZnFe2O4 into the TiO2/C could enhance the absorption spectrum range. The ZnFe2O4–TiO2/C hybrids exhibited a higher photocatalytic activity both than that of the pure TiO2 and TiO2/C under either UV or simulated solar light irradiation. The complex synergistic effect plays an important role in improving the photocatalytic performance of ZnFe2O4–TiO2/C composites. The optimum photocatalytic performance was obtained from the ZnFe2O4(0.8 wt%)–TiO2/C sample.