Decolorization of methylene blue by heterogeneous Fenton reaction using Fe3-xTixO4 (0 ≤ x ≤ 0.78) at neutral pH values

In this work, a series of Fe3-xTixO4 (0 <= x <= 0.78) was synthesized using a new soft chemical method. The synthetic Fe3-xTixO4 were characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Mossbauer spectroscopy, thermogravimetric and differential scanning calorimetry (TG-DSC) analyses. The results showed that they were spinel structures and Ti was introduced into their structures. Then, decolorization of methylene blue (MB) by Fe3-xTixO4 in the presence of H2O2 at neutral pH values was studied using UV-vis spectra, dissolved organic carbon (DOC) and element C analyses. Furthermore, the degradation products remained in reaction solution after the decolorization were identified using ionic chromatography (IC), C-13 nuclear magnetic resonance spectra (NMR), liquid chromatography and mass spectrometry (LC-MS). Although small amounts of MB were mineralized, the aromatic rings in MB were destroyed completely after the decolorization. Decolorization of MB by Fe3-xTixO4 in the presence of H2O2 Was promoted remarkably with the increase of Ti content in Fe3-xTixO4 due to the enhancement of both adsorption and degradation of MB on Fe3-xTixO4. (C) 2009 Elsevier B.V. All rights reserved.