Preparation of magnetite-nanoparticle-decorated NiFe layered double hydroxide and its adsorption performance for congo red dye removal

Magnetite-nanoparticle-decorated NiFe LDH (MNPs@NiFe LDH) has been synthesized by the coprecipitation method followed by subsequent hydrothermal treatment. Material characterization was conducted using XRD, FTIR, SEM, BET surface area, and TG-DTA. MNPs@NiFe LDH exhibited high crystallinity, where the MNPs are uniformly distributed on its surface. MNPs@NiFe LDH showed higher adsorption capacity for congo red dye removal from an aqueous solution (79.6 mg/g). A further adsorption study, kinetics, isotherm, and thermodynamic indicated that the adsorption mechanism is governed by ionic interaction between the positively charged surface of the LDH and negatively charged dye molecules.