In the present work, we synthesized successfully novel magnetic montmorillonite composite γ-Fe₂O₃@Mt by a facile co-precipitation method of Fe²⁺ and Fe³⁺ in alkaline solution in the presence of montmorillonite clay mineral. The structural, morphological and chemical properties of the γ-Fe₂O₃@Mt samples were characterized by Fourier transform infrared spectroscopy, Thermogravimetric Analysis/differential thermal analysis, Scanning Electron Microscopy/Energy Dispersive X-Ray Spectroscopy, Energy Dispersive X-Ray Spectroscopy/Elemental Mapping, Transmission electron microscopy, X-ray diffraction, Brunauer–Emmett–Teller surface area, zeta potential and magnetic properties. The adsorption process of Rhodamine B (cationic dye) onto γ-Fe₂O₃@Mt was examined as a function of adsorbent amount, pH, contact time and initial dye concentration. The maximum quantity adsorbed of RhB dye onto Fe₂O₃@Mt was found as 209.20 mg/g. The kinetic study indicated that the adsorption equilibrium of Rhodamine B dye onto γ-Fe₂O₃@Mt was obtained after 25 min. The adsorption isotherms were described by Langmuir isotherm model suggesting that the Rhodamine B dye molecules are adsorbed homogeneously on a monolayer surface of γ-Fe₂O₃@Mt. The experimental data were well fitted to a pseudo-second-order kinetic model (R² > 0.99). A Computational modeling was performed in order to obtain deeper mechanistic insights on the adsorption behaviour of the RhB dye molecules onto γ-Fe₂O₃@Mt.composite.

This modeling section include Monte Carlo space exploration for the lowest adsorption energy configurations of the RhB molecule on the raw Mt. substrate and the different γ-Fe₂O₃ flat nanosurfaces, followed by molecular dynamics simulation of the titled dye molecules on real cylindrical maghemite nanosurface.