Adsorption mechanism and electrochemical performance of methyl blue onto magnetic Ni(1-x-y)CoyZnxFe2O4 nanoparticles prepared via the rapid-combustion process

Abstract Magnetic Ni(1-x-y)CoyZnxFe2O4 nanoparticles are prepared via the rapid-combustion process, which are characterized by XRD, VSM, SEM, EDS and FTIR, and the effects of absolute alcohol volume and the calcination temperature on the properties of magnetic Ni–Co–Zn ferrite nanoparticles are also investigated. To obtain the maximum adsorption capacity, Ni0.3Co0.4Zn0.3Fe2O4 nanoparticles calcined at 400 °C for 2 h with 20 mL of absolute alcohol are selected to adsorb methyl blue (MB). The adsorption results illustrate that pseudo-second-order model and Langmuir isotherm model are the best fit, which indicates that the adsorption of MB onto the nanoparticles is the monolayer chemical adsorption. The effect of the pH value on the adsorption and the recycling performance of Ni0.3Co0.4Zn0.3Fe2O4 nanoparticles are investigated. When the initial concentration of MB is 300 mg/L and the pH value is 5, the adsorption capacity of MB onto Ni0.3Co0.4Zn0.3Fe2O4 nanoparticles reaches 101.1 mg/g, while the adsorption capacity amounts to 71.7% of the first time after 8 recycles. The electrochemical performances of MB onto Ni0.3Co0.4Zn0.3Fe2O4 nanoparticles before and after adsorption are analyzed by CV and EIS.