A facile sol combustion and calcination process for the preparation of magnetic Ni0.5Zn0.5Fe2O4 nanopowders and their adsorption behaviors of Congo red

A facile sol combustion and calcination process for the preparation of magnetic Ni0.5Zn0.5Fe2O4 nanopowders was introduced and the gel precursor and as-prepared nanopowders were characterized by TG/DSC, XRD, BET, SEM and TEM. The results have shown that the single ferrite phase of Ni0.5Zn0.5Fe2O4 can be formed at 400 °C. It can be indicated that the volume of the solution is a key factor to the properties of the magnetic Ni0.5Zn0.5Fe2O4 nanopowders: with the volume of absolute alcohol increasing from 10 mL to 30 mL, the average grain sizes of Ni0.5Zn0.5Fe2O4 powders calcined at 400 °C for 2 h with the heating rate of 3 °C/min increase from about 14.9 nm to 18.3 nm, while the saturation magnetizations increase from about 27.1 Am2/kg to 105.2 Am2/kg, and the specific surface area is up to maximum of 69.7 m2/g when absolute alcohol is 15 mL. The adsorption kinetics and adsorption isotherm of Congo red (CR) onto the magnetic Ni0.5Zn0.5Fe2O4 nanoparticles calcined at 400 °C for 2 h with a heating rate of 3 °C/min and absolute alcohol of 15 mL were investigated at room temperature. The kinetic data related to the adsorption of CR from aqueous solutions are in good agreement with the pseudo-second-order kinetic model with a range of initial concentrations of 100–500 mg/L. Compared with Langmuir and Freundlich models for adsorption isotherm of CR, Temkin model (correlation coefficient R2 = 0.9937) can be used to evaluate the CR adsorption isotherm at room temperature.

The magnetic Ni0.5Zn0.5Fe2O4 nanopowders were prepared via the facile sol combustion and calcination process with absolute alcohol as fuel, their properties were characterized, and the adsorption kinetics and adsorption isotherms of CR onto magnetic Ni0.5Zn0.5Fe2O4 nanopowders at room temperature were analyzed.Figure optionsDownload as PowerPoint slide