Graphene based nanocomposites enhanced Fenton process for azo dye degradation

Abstract

The design and fabrication of smart and low-cost nanocomposites (NCs) is still an area of challenge in wastewater treatment. In this context, firstly individual graphene oxide (GO) and cerium oxide (CeO₂) nanoparticles (NPs) were synthesized by precipitation method. This was followed by synthesis of GO-CeO₂-NCs by mixing GO and CeO₂-NPs in natural surfactant which was characterized by UV–visible absorption spectroscopy. The morphology of the synthesized GO-CeO₂-NCs was established by scanning electron microscopy (SEM) studies while high resolution transmission electron microscopy (HRTEM) analysis revealed shape and particle size of the synthesized NCs. Fourier transform infrared spectroscopy (FTIR) was used to confirm the presence of different functional groups in the synthesized GO-CeO₂-NCs and thermal stability was determined by thermal gravimetric analysis (TGA). The synthesized GO-CeO₂-NCs was used as catalyst in heterogeneous Fenton process for the degradation of methyl violet (MV) dye. The effects of various experimental parameters, i.e., pH, H₂O₂, GO-CeO₂ NCs for MV degradation were investigated to have optimum condition. The optimum conditions for effective degradation with 98 % was achieved just within 100 minutes, at pH=8, [H₂O₂] 80×10⁻⁴ M, and [GO-CeO₂] 18 mg/L for 3×10⁻³ M degradation. The experimental observations have led up to propose a most plausible mechanism for GO-CeO₂-NCs enhanced Fenton’s degradation of MV. GO-CeO₂ nanocomposites with H₂O₂ shows amazing removal capacities in the elimination of MV. In summary, synthesized GO-CeO₂ nanocomposites demonstrate remarkable efficiency in present work, and offering a promising solution for the effective degradation of methyl violet dye in wastewater treatment.