Facile synthesis of Fe3O4 nanoparticles via aqueous based electro chemical route for heterogeneous electro-Fenton removal of azo dyes

Ferro magnetic iron oxide (Fe3O4) nanoparticles (NPs) were prepared through a facile and inexpensive electrochemical method. Characterization studies on the generated magnetite nanoparticles (MNPs) was carried out using X-Ray diffraction pattern (XRD), Fourier transform infrared (FTIR), field emission scanning electron microscope (FESEM), dynamic light scattering (DLS) and vibrating sample magnetometer (VSM) analysis. The synthesized material was used as a heterogeneous electro-Fenton catalyst in order to decolorize C.I. Acid Red 14 and C.I. Acid Blue 92 solutions. Graphite electrode Modified with carbon nanotubes (CNTs) were used as cathode in both synthesis and electro-Fenton processes. The effect of operational factors like pH range, initial dye concentration, Fe3O4 loading, current intensity and electrolyte (NaCI) dosage on dye removal efficiency was investigated. Remarkable discoloration in wide range of pH illustrated the superior catalytic potential of MNPs. Furthermore, the recyclability of Fe3O4 NPs after magnetic separation, the prevention of their entrance into the environment as a secondary pollutant and the promoted electro generation of hydrogen peroxide at the surface of cathode due to the presence of CNTs are the additional advantages of this study. (C) 2016 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.