Preparation Of Magnetic Graphene Oxide Composites And Properties Of Their Adsorption Dyes

The extensive use of dye has brought great pollution problem,and it has also become a touch challenge which needed to be solved urgently.Adsorption method has shown great practical potentiality in water purification.Fe3O4/GO and Fe3O4/GO/CS composite were prepared by precipitation under ultrasonic radiation,the morphology,chemical structure and magnetic properties of composites were characterized by scanning electron microscope(SEM),X-ray powder diffraction(XRD),Fourier Transform Infrared Spectroscopy(FTIR)and vibrating sample magnetometer(VSM).Batch experiments were carried out to investigate the effect of solution pH,adsorbent dosage,contact time on sorption efficiency and the adsorption kinetics,isothems were investigated.The results showed that Fe3O4/GO and Fe3O4/GO/CS composite with paramagnetic property was prepared successfully,so that they could be utilized as magnetically separable adsorbents under external magnetic field;The maximum adsorption capacity of Fe3O4/GO composite for methyl orange was 139.7mg/g and for neutral red was 277.0 mg/g;the removal of dye increases with the increase of the adsorbent dosage;the removal efficiency of dye grown fast at the initial stage,then increased slowly,and adsorption equilibrium appeared at last state and the adsorption equilibrium were reached within 24 h;The adsorption process fitted pseudo-second-order and the Langmuir model,which revealed that the adsorption process is spontaneous and chemical.Fe3O4/GO composite and Fe3O4/GO/CS composite may perform well for the sorption of neutral red in a wide range of pH value and the maximum adsorption capacity of Fe3O4/GO/CS composite for neutral red was 296.7 mg/g,the removal of dye increases with the increase of the adsorbent dosage;the removal efficiency of dye grown fast at the initial stage,then increased slowly,and adsorption equilibrium appeared at last state and the adsorption equilibrium were reached within 24 h;the adsorption equilibrium data and kinematic data showed good correlation with psudo-second-order model and Langmuir isotherm models,which revealed that the adsorption process is spontaneous and chemical.Fe3O4/GO/CS composite could be utilized as an efficient,magnetically separable adsorbent.Therefore,it has great potential as adsorbent for the treatments of dye wastewater.