Magnetic Ti3C2 MXene Nanomaterials for Doxorubicin Adsorption from Aqueous Solutions: Kinetic, Isotherms, and Thermodynamic Studies.

Abstract

In this work, the magnetic Ti3C2 MXene functionalized with β-cyclodextrin was prepared and characterized using scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectra, X-ray diffraction, X-ray photoelectron spectroscopy, vibrating sample magnetometry, and thermogravimetric analysis. The synthesized nanomaterial was used as an adsorbent to adsorb doxorubicin from aqueous solutions, and the experimental parameters that affected the adsorption efficiency were investigated. In addition, the adsorption characteristics including adsorption kinetics, adsorption isotherm, and thermodynamics were researched comprehensively. The adsorption kinetics of doxorubicin followed a pseudo-second-order kinetic model, which indicated that adsorption was the rate-limiting step, and the maximum adsorption capacity was 7.35 μg mg–1 by shaking for 60 min at pH 7.0. The adsorption isotherm was well described using the Freundlich model, which implied that multilayer adsorption took place over the prepared nanomaterial for doxorubicin adsorption. The negative values of Gibbs free energy change (ΔG0 < 0) demonstrated that doxorubicin adsorption was a spontaneous process. The positive values of entropy change (ΔS0 > 0) implied that doxorubicin adsorption was an increasing random process. Enthalpy change values were positive (ΔH0 > 0) and indicated that the adsorption of doxorubicin was endothermic. The adsorption percentage of doxorubicin remained in the range of 41.05–44.09%, and the relative standard deviation (RSD) based on the adsorption percentage through five replicate adsorption and desorption processes was 2.8%. These results indicated that the magnetic Ti3C2 MXene nanomaterials can be an effective adsorbent to adsorb DOX from aqueous solutions.