The impact of H2O/C2H5OH solvents on the properties of Fenton CuFe2O4 photocatalysts for the degradation reaction of methylene blue

Abstract

This paper reported a simple method of co-precipitation in aqueous and ethanol solvent systems to prepare a catalyze CuFe2O4 heterogeneous Fenton used for the degradation reaction of methylene blue (MB). The mixtures of oxalate precursors were prepared from the corresponding sulfate salts and oxalic acid in the solvent system of H2O/C2H5OH. The heat treatment of the precursor mixtures was carried out at 600, 700, and 800 oC in the surrounding atmosphere. The change in the volume ratio of water and ethanol with the tendency to gradually decrease the volume of water lead to a decrease in the polarity of the solvent and affected the precursors' precipitation as well as the solid phase reaction. The decrease in the solvent polarity resulted in a slight increase of the particle size and a reduction of the crystallinity. The experimental results showed that the water-ethanol solvent system had the effect of reducing the degree of dispersion in terms of the particle size. Meanwhile, the increase of the precursor calcination temperature resulted in the increased grain size and the higher concentration of Fe3+ ions on the surface compared with samples heat-treated at 600 and 800 oC. Samples, prepared from the solvent system with the ethanol-water volume of 50% or 70%, and then were calcined at 700 oC, showed good catalytic ability for the MB decomposition reaction irradiated by UVA rays and oxalic acid being used as an oxidizing agent. The MB processing efficiency after 90 minutes was 85%.