Graphene oxide-MnFe2O4 nanohybrid material as an adsorbent of Congo red dye

The aim of this work is the synthesis and characterization of graphene oxide (GO)-MnFe2O4 nanohybrid material, as well as the study of its performance in the removal of Congo red (CR) dye from aqueous solutions. The GO-MnFe2O4 was prepared via a three-step method. Firstly, GO was produced via a modified Hummers' method, using graphite powder as starting material. Subsequently, GO was functionalized with ionic surfactants, cetyltrimethylammonium bromide and poly(sodium-4-styrenesulfonate). Following this, the functionalized GO was decorated with magnetic MnFe2O4 nanoparticles via an electrostatic self-assembly process using a solvothermal treatment at 200 degrees C for 12 h. The as-prepared GO-MnFe2O4 nanohybrid material was characterized by several techniques: X-ray diffraction analysis, Fourier-transform infrared spectroscopy, micro-Raman spectroscopy, thermogravimetric analysis, field emission scanning electron microscopy, and high-resolution transition electron microscopy with energy-dispersive spectroscopy mapping. The adsorption performance of GO-MnFe2O4 in the removal of CR dye was evaluated at different initial CR concentrations and contact times using an ultraviolet-visible spectrophotometer. In addition, its recyclability performance was investigated for 10 cycles. It is noteworthy that even after the last cycle, the removal efficiency of GO-MnFe2O4 exceeded 65%, indicating that the adsorbent had very good reusability. Finally, the Freundlich isotherm model yielded a better fit for the adsorption data, compared to Langmuir, while adsorption of CR by GO-MnFe2O4 showed pseudo-second-order kinetics.

Automated summary

The aim of this work is to synthesize and characterize a graphene oxide (GO)-MnFe2O4 nanohybrid material and study its effectiveness in removing Congo red (CR) dye from water. The GO-MnFe2O4 was prepared through a three-step method, including the production of GO using graphite powder and the decoration of GO with magnetic MnFe2O4 nanoparticles. The as-prepared GO-MnFe2O4 nanohybrid material was thoroughly characterized through various techniques. The adsorption performance of GO-MnFe2O4 in removing CR dye was evaluated, showing excellent reusability even after multiple cycles.