MgFe2O4 and MgFe2O4/ZnFe2O4 coated with polyaniline as a magnetically separable photocatalyst for removal of a two dye mixture in aqueous solution

In this work MgFe2O4 and MgFe2O4/ZnFe2O4 coated with polyaniline (PANI) as an efficient magnetically separable photocatalyst were synthesized. The prepared samples were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, BET analysis, field emission scanning electron microscopy and energy dispersive X-ray analysis. The adsorption and photocatalytic activity of the samples for removal of a two dye mixture of methylene blue and methyl orange in aqueous solution were examined. The results indicate that the MgFe2O4/PANI sample is a promising candidate for effective photodecolorization of both methylene blue and methyl orange dyes in aqueous solution. For the MgFe2O4/ZnFe2O4/PANI sample, a large amount of the removal of the methylene blue via adsorption and photocatalytic experiments was observed. The prepared samples demonstrated the high removal ability after five repeated utilizations. The pseudo-first and pseudo-second order kinetic models were used to describe the adsorption kinetic data. It was observed that the pseudo-second order kinetic model described the adsorption process better than pseudo-first order.