Fe3O4-GO composite as efficient heterogeneous photo-Fenton's catalyst to degrade pesticides

Magnetic iron oxide (Fe3O4) and its composite with graphene oxide (Fe3O4-GO) were synthesized via ultrasonic-assisted co-precipitation method and characterized by Scanning Electron Microscopy, Fourier Transform Infrared spectroscopy and x-ray Diffraction techniques. These magnetic catalysts were investigated as heterogeneous photo-Fenton catalysts to degrade selected pesticides (carbofuran and nitenpyram) under UV light. The detailed parametric study explained that optimum catalyst dose and oxidant concentration were responsible for better catalytic degradation of pesticides. Degradation studies using magnetite alone was also performed in order to visualize the role of GO in catalysis. The composite Fe3O4-GO performed excellently in comparison to Fe3O4 for pesticides degradation. More than 90% degradation of nitenpyram and carbofuran were achieved. In order to have deep insight of the interaction between various process parameters, optimization through Response Surface Methodology (RSM) was studied for Fe3O4-GO. It has been found that no iron hydroxide sludge is formed when using Fe3O4-GO. Also the catalytic degradation could be reproduced in consecutive experiments without a significant loss in the process efficiency.