Degradation of methyl orange by heterogeneous Fenton-like oxidation on a nano-organometallic compound in the presence of multi-walled carbon nanotubes

In this study, heterogeneous Fenton-like processes using ferrocene groups immobilized on aluminum-silicate nanoparticles and multi-walled carbon nanotubes (Si/Al@Fe/MWCNT) show a high degradation and decolorization efficiency for methyl orange (MO). The effects of several parameters such as pH, initial H2O2 concentration, reaction time, catalyst loading, and temperature on the oxidative degradation and decolorization of MO have been studied. The seven cycles of the Fenton-like processes utilizing the aforementioned catalyst showed the steady removal of MO, thereby demonstrating the high stability of the Si/Al@Fe/MWCNT system over several Fenton oxidation processes. Scavenging of the HO center dot produced in the reaction media was assessed using n-butanol and KI and confirmed that this radical, which is generated upon decomposition of H2O2, is mainly responsible for the heterogeneous Fenton like oxidation of MO. A feasible Fenton-like oxidation pathway for MO in the presence of the Si/Al@Fe/MWCNT nanocatalyst was proposed. Finally, the degradation of various dyes using the Si/Al@Fe/MWCNT system was compared. (C) 2016 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.