Characterization and evaluation catalytic efficiency of NiFe2O4 nano spinel in removal of reactive dye from aqueous solution

In this paper, the spinel-type NiFe2O4 nanoparticles have been fabricated by sol–gel method and characterized by differential thermal analysis (DTA), X-ray powder diffraction (XRD), Fourier infrared spectroscopy (FT-IR), scanning electron microscopy (STM) and transmission electron microscopy (TEM). The average particle size of NiFe2O4 is about 17 nm. The nanospinel NiFe2O4 showed the excellent adsorption properties towards reactive blue 5 (RB5) as a reactive dye. The adsorption studies have been carried out at different pH values, temperatures, and adsorbent doses to find the optimum conditions. At pH = 1 and 25 °C, the removal of RB5 above 90% was achieved. The removal process follows the pseudo-second-order kinetics and the Freundlich adsorption isotherm model. Thermodynamic study indicates that the adsorption of RB5 is feasible, and spontaneous in nature.