Adsorption Performance of Neutral Red onto Magnetic Cu _x Zn_(1–x)Fe₂O₄ Nanoparticles Prepared via the Solution Combustion Process

A facile solution combustion process for the preparation of magnetic Cu _x Zn_(1–x)Fe₂O₄ nanoparticles was introduced. The experimental results showed that the content of Cu in Cu _x Zn_(1–x)Fe₂O₄ nanoparticles, the volume of absolute alcohol and the calcination temperature were three key factors to grain size, crystallinity and properties of magnetic Cu _x Zn_(1–x)Fe₂O₄ nanoparticles. When the content of Cu in Cu _x Zn_(1–x)Fe₂O₄ nanoparticles was 0.5, the grain size was relatively smaller. With the volume of absolute alcohol increasing from 10 to 30 mL, the average grain size of Cu_0.5Zn_0.5Fe₂O₄ nanoparticles decreased firstly from 19.4 nm to 13.8 nm, then the average grain size increased from 13.8 nm to 18.9 nm; with absolute alcohol increasing from 30 to 100 mL, while the saturation magnetization (M_s ) value of Cu_0.5Zn_0.5Fe₂O₄ nanoparticles increased from 2.0 emu/g to 22.8 emu/g. With the calcination temperature increasing from 400 °C to 800 °C, the average grain size increased from 19.4 nm to 37.0 nm, and the saturation magnetization value increased from 22.8 emu/g to 47.2 emu/g. The magnetic Cu_0.5Zn_0.5Fe₂O₄ nanoparticles were employed to remove neutral red (NR) from aqueous solution, the adsorption kinetic of NR onto the magnetic Cu_0.5Zn_0.5Fe₂O₄ nanoparticles calcined at 700 °C for 2 h with the heating rate of 3 °C/min and absolute alcohol of 20 mL was investigated at room temperature. The kinetic data related to the adsorption of NR from aqueous solutions were in good agreement with the pseudo-second-order kinetic model with the initial NR concentrations of 50–300 mg/L.