Adsorption Performances and Electrochemical Characteristic of Methyl Blue onto Magnetic MgxCu(1-x)Fe2O4 Nanoparticles Prepared via the Rapid Combustion Process

Magnetic MgxCu(1-x)Fe2O4 nanoparticles were prepared by the rapid combustion method, and characterized by TEM, VSM and XRD techniques. For larger specific surface area and larger adsorption capacity, magnetic Mg0.5Cu0.5Fe2O4 nanoparticles calcined at 400 ºC for 2 h with an average particle size of 32.3 nm were employed to remove methyl blue (MB), and the adsorption mechanism of MB onto Mg0.5Cu0.5Fe2O4 nanoparticles was investigated. The correlation coefficient (R2) values of the second-order kinetic model and Freundlich model for fitting the adsorption data of MB onto Mg0.5Cu0.5Fe2O4 nanoparticles reached more than 0.99, which suggested that the adsorption of MB onto Mg0.5Cu0.5Fe2O4 nanoparticles belonged to the chemical multilayer adsorption mechanism. When pH ≥ 3, the adsorption capacity reached maximum of 159 mg/g. However, when pH < 3, the adsorption capacity kept a minor value, which indicated that the adsorption capacity could be controlled by changing pH value. After 12 cycles, the adsorption capacities of the Mg0.5Cu0.5Fe2O4 nanoparticles could still reach 83