Preparation And Adsorption Properties On Dyes Of Cobalt Ferrite Composite Nanomaterials

Spinel cobalt ferrite is a typical ferrimagnetic compound.Cobalt ferrite nanoparticles possess excellent electromagnetic properties and good chemical stability.In this thesis,magnetic CoFe2O4/graphene oxide(GO)adsorbents are synthesized by a facile hydrothermal method.Structure,morphology and physicochemical properties of the adsorbents were analyzed by XRD,FTIR,Raman spectroscopy,SEM,TGA and VSM.The results show that the as-synthesized CoFe2O4/GO adsorbents exhibit remarkable adsorption behavior for methyl blue(MB),rhodamine B(RhB)and methyl orange(MO).Impressively,almost no adsorption of the above three dyes for the as-synthesized CoFe2O4 is detected,which confirms that adsorption performance of organic dyes for the CoFe2O4/GO composite mainly originates from the contribution of GO.Here,an obvious selective adsorption behavior can be observed,where the order of adsorption capacity MB>RhB>MO.The corresponding adsorption kinetics and isotherms are discussed.The adsorption process conforms to the pseudo-second-order model and Langmuir isotherm model.Noticeably,from Langmuir model,a superior adsorption capacity Qe(ma.)for MB and RhB was 355.9 mg/g and 284.9 mg/g.According to the fitting result of adsorption kinetic model,the adsorption of dye by GO is mainly due to the electrostatic interaction between GO and dye molecule and the π-π stacking of carbon ring.Due to the introduction of CoFe2O4 nanoparticles,the composite exhibits remarkable magnetic properties,which makes it be easily separated from aqueous solution.Additionally,in terms of the molecular dynamics method,we systematically calculated adsorption configurations and adsorption energies to investigate the interaction of dye molecules with CoFe2O4/GO composites.Our research gives a profound insight on the adsorption mechanism of CoFe2O4/GO composites,the combination of experiment and simulation proposes a new design thought to develop new materials.